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                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                   FORM N-CSR

                   CERTIFIED SHAREHOLDER REPORT OF REGISTERED
                        MANAGEMENT INVESTMENT COMPANIES



		Investment Company Act file number 811-21321

                          Pioneer Municipal High Income Trust
               (Exact name of registrant as specified in charter)


                       60 State Street, Boston, MA 02109
              (Address of principal executive offices) (ZIP code)


            Terrence J. Cullen, Pioneer Investment Management, Inc.,
                       60 State Street, Boston, MA 02109
                    (Name and address of agent for service)


Registrant's telephone number, including area code:  (617) 742-7825


Date of fiscal year end:  April 30


Date of reporting period:  May 1, 2014 through October 31, 2014


Form N-CSR is to be used by management investment companies to file reports with
the Commission not later than 10 days after the transmission to stockholders of
any report that is required to be transmitted to stockholders under Rule 30e-1
under the Investment Company Act of 1940 (17 CFR 270.30e-1).  The Commission may
use the information provided on Form N-CSR in its regulatory, disclosure review,
inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-CSR,
and the Commission will make this information public. A registrant is not
required to respond to the collection of information contained in Form N-CSR
unless the Form displays a currently valid Office of Management and Budget
("OMB") control number. Please direct comments concerning the accuracy of the
information collection burden estimate and any suggestions for reducing the
burden to Secretary, Securities and Exchange Commission, 450 Fifth Street, NW,
Washington, DC 20549-0609.  The OMB has reviewed this collection of information
under the clearance requirements of 44 U.S.C. ss. 3507.


ITEM 1. REPORTS TO STOCKHOLDERS.


                        Pioneer Municipal High
                        Income Trust

--------------------------------------------------------------------------------
                        Semiannual Report | October 31, 2014
--------------------------------------------------------------------------------

                        Ticker Symbol: MHI

                        [LOGO] PIONEER
                               Investments(R)


                       visit us: us.pioneerinvestments.com


Table of Contents


                                                                          
President's Letter                                                            2

Portfolio Management Discussion                                               4

Portfolio Summary                                                            10

Prices and Distributions                                                     11

Performance Update                                                           12

Schedule of Investments                                                      13

Financial Statements                                                         22

Financial Highlights                                                         25

Notes to Financial Statements                                                27

Approval of Investment Advisory Agreement                                    35

Trustees, Officers and Service Providers                                     40


            Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 1


President's Letter

Dear Shareowner,

As we move into the final months of 2014, we remain confident that U.S. economic
growth remains self-sustaining despite weakness in foreign economies, and that
the expansion will continue until the economy reaches full employment.
Unemployment has ticked down below 6% and the number of job openings is at the
highest level since 2000, while the number of people filing initial unemployment
claims has fallen to the lowest level in fourteen years. Wage growth, while
still low, is outpacing inflation, consumer debt burdens are modest and lower
gasoline prices are freeing up discretionary spending power.

The global economic picture is less rosy, however, as the conflict between
Russia and the Ukraine is exacting a toll on the European economy, Japan is
still working through the impact of its large tax increase, and the growth of
China's investment-driven economy has been slowing. There are also geopolitical
and other threats to the outlook, such as the Ebola virus outbreak and the
advance of ISIS in key areas of the Middle East. On balance, though, we expect
the global economy to continue to grow over the remainder of 2014 and in 2015.

While our economic outlook is generally constructive and we believe
opportunities remain for prudent investors to earn attractive returns, markets
are likely to continue to be volatile, a scenario that offers the potential for
rewards, but for increased risks as well.

Since 1928, Pioneer's investment professionals have worked on behalf of our
shareholders, incorporating proprietary research to find attractive investment
opportunities and prudent risk management to construct portfolios.

We continue to advocate the benefits of adhering to a disciplined investment
strategy and encourage you to work with your financial advisor to develop and
implement an overall investment plan that addresses both your short- and
long-term goals.

2 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


On August 11, 2014, I joined Pioneer as the new President and CEO of Pioneer
Investment Management USA, Inc. In my role, I will focus on preserving many of
the rich qualities of our history, while meeting the challenges and capitalizing
on the opportunities presented by an ever-changing world.

We greatly appreciate your trust in us in the past and look forward to
continuing to serve you in the future.

Sincerely,

/s/ Lisa M. Jones

Lisa M. Jones
President and CEO
Pioneer Investment Management USA, Inc.

Any information in this shareowner report regarding market or economic trends or
the factors influencing the Trust's historical or future performance are
statements of opinion as of the date of this report. These statements should not
be relied upon for any other purposes. Past performance is no guarantee of
future results, and there is no guarantee that market forecasts discussed will
be realized.

            Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 3


Portfolio Management Discussion | 10/31/14

Municipal bonds, both investment-grade and high-yield, delivered solid returns
over the six-month period ended October 31, 2014. In the following interview,
David Eurkus and Jonathan Chirunga discuss the factors that influenced the
performance of Pioneer Municipal High Income Trust during the six-month period
ended October 31, 2014. Mr. Eurkus, Director of Municipals, a senior vice
president and a portfolio manager at Pioneer, and Mr. Chirunga, a vice president
and a portfolio manager at Pioneer, are responsible for the day-to-day
management of the Trust.

Q   How did Pioneer Municipal High Income Trust perform during the six-month
    period ended October 31 2014?

A   Pioneer Municipal High Income Trust returned 5.35% at net asset value and
    6.53% at market price during the six-month period ended October 31, 2014.
    During the same six-month period, the Trust's benchmarks, the Barclays High
    Yield Municipal Bond Index and the Barclays Municipal Bond Index, returned
    4.62% and 3.59% at net asset value, respectively. The Barclays High Yield
    Municipal Bond Index is an unmanaged measure of the performance of
    lower-rated municipal bonds, while the Barclays Municipal Bond Index is an
    unmanaged measure of the performance of investment-grade municipal bonds.
    Unlike the Trust, the two Barclays indices do not use leverage. While use
    of leverage increases investment opportunity, it also increases investment
    risk.  During the same six-month period, the average return (at market
    price) of the 11 closed end funds in Lipper's High Yield Municipal Debt
    Closed End Funds category (which may or may not be leveraged) was 4.96%.

    The shares of the Trust were selling at a 13.0% premium to net asset value
    at the end of the period, on October 31, 2014.

    On October 31, 2014, the standardized 30-day SEC yield of the Trust's
    shares was 4.18%*.

Q   How would you describe the investment environment in the municipal bond
    market during the six-month period ended October 31, 2014?

A   The past six months featured a favorable environment for municipal bonds,
    which continued to rally as they had throughout much of 2014. Both
    traditional tax-conscious investors and non-traditional buyers recognized
    the attractive values available in the municipal market, especially
    relative to

*   The 30-day SEC yield is a standardized formula that is based on the
    hypothetical annualized earning power (investment income only) of the
    Trust's portfolio securities during the period indicated.

4 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


    the low-yielding taxable fixed-income market. Over the six-month period,
    high-yield municipal securities maintained a performance edge over
    higher-quality municipal bonds during a market surge sustained by increasing
    investor confidence in the strength of the domestic economy and, more
    specifically, in the credit-worthiness of the municipalities and
    institutions issuing tax-exempt bonds. The rally was enhanced as longer-term
    interest rates declined and long- and intermediate-term bonds generally
    appreciated in price during the period.

    During the period, investor confidence increased due to the growing
    belief that the financial markets would absorb the end of the U.S. Federal
    Reserve System's (the Fed's) quantitative easing bond-purchasing program
    without any significant disruption. Meanwhile, confidence in the credit
    quality of municipal bonds remained high as the market seemed to recognize
    that the debt problems of some individual municipal issuers did not reflect
    overall conditions in the municipal market, which were largely positive. In
    addition, municipal bond default rates remained low by historical standards.

    While demand for municipal debt in general, and higher-yielding municipal
    bonds in particular, grew during the period, a decline in new security
    issuance limited the supply of municipal bonds in the market, and that
    supply/demand factor resulted in price appreciation for most municipal
    bonds. Also, the tightening of yield spreads - or yield advantages - of
    higher-yielding municipals compared with higher-quality municipals led the
    high-yield municipal market to outperform the general municipal market
    during the six-month period.

Q   What were the major factors that influenced the performance of the Pioneer
    Municipal High Income Trust relative to the Barclays indices, the Trust's
    benchmarks, during the six-month period ended October 31, 2014?

A   The Trust outperformed the Barclays indices during the period, with the
    portfolio's relatively long duration proving to be a key advantage, as
    long- and intermediate-term securities performed quite well in a declining
    interest-rate environment. (Duration is a measure of the sensitivity of the
    price - the value of principal - of a fixed-income investment to a change in
    interest rates, expressed as a number of years.)

    Individual portfolio holdings that helped to support the Trust's
    benchmark-relative results during the period included: education bonds
    issued by the University of California; zero-coupon bonds of the
    Metropolitan Pier and Exposition Authority of Chicago; non-callable
    securities of the Massachusetts Development Authority; and hospital/health
    care bonds of Temple University Healthcare.

            Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 5



    The Trust's portfolio did have some positions that produced disappointing
    performance during the period, including bonds backed by correctional
    facilities in Liberty County, Florida and Central Falls, Rhode Island, and a
    pool of high-yield bonds issued by Non-Profit Preferred Funding Trust.

Q   How did the level of leverage in the Trust change over the six-month
    period ended October 31, 2014?

A   At the end of the six-month period on October 31, 2014, 24.8% of the Trust's
    total managed assets were financed by leverage obtained through the issuance
    of preferred shares, compared with 25.1% of the Trust's total managed assets
    financed by leverage at the beginning of the six-month period on May 1,
    2014. However, the dollar amount of the funds obtained through the issuance
    of preferred shares did not change during the period. The percentage
    decrease was due to an increase in the values of securities in which the
    Trust had invested.

Q   Did you use any derivatives in managing the Trust's portfolio during the
    six-month period ended October 31, 2014?

A   No, the Trust had no exposure to derivatives during the period.

Q   What is your investment outlook?

A   We have a positive outlook for the municipal bond market in
    general, including both investment-grade and high-yield municipals. We
    anticipate that the domestic economy should continue to grow moderately,
    which may help to support the improvements in the financial health of
    municipalities and public agencies that issue municipal bonds. The domestic
    employment situation continues to improve and consumer spending has been
    increasing, while inflation remains low. The Fed, even with its quantitative
    easing program at an end, has maintained low short-term interest rates,
    which we believe are likely to remain at present levels until at least
    mid-2015.

    This is not to say, however, that there are not areas of concern. While
    unemployment rates are down, labor force participation rates also are
    lower.  Moreover, the potential effects of declining global economic growth
    on the domestic economy remain a concern, as signs of weakness or slowing
    growth rates have appeared in most major foreign economies, including
    those in China, Europe, Japan, and commodity-exporting emerging markets.
    Over the shorter term, however, the slowing of global growth has
    accelerated the movement of money flows into the U.S., thus helping to
    strengthen the U.S. dollar, while at the same time pushing market interest
    rates in the United States - including those in the municipal market - to
    lower levels.

6 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14



    The municipal market remains healthy, with strong demand and a limited
    supply of securities available for investment. At the same time, we believe
    municipal bonds still offer attractive value, particularly for
    tax-conscious investors. Going forward, we plan to maintain our emphasis on
    fundamental credit research when selecting securities for the Trust's
    portfolio, and to maintain a well-diversified** portfolio of securities,
    with a focus on project-revenue bonds backed by specific income streams.

** Diversification does not assure a profit nor protect against loss in a
   declining market.

            Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 7


Please refer to the Schedule of Investments on pages 13-21 for a full listing of
Trust securities.

Investments in high-yield or lower-rated securities are subject to
greater-than-average risk.

The Trust may invest in securities of issuers that are in default or that are in
bankruptcy.

A portion of income may be subject to state, federal, and/or alternative minimum
tax. Capital gains, if any, are subject to a capital gains tax.

When interest rates rise, the prices of debt securities held by the Trust will
generally fall. Conversely, when interest rates fall the prices of debt
securities held by the Trust generally will rise.

By concentrating in municipal securities, the Trust is more susceptible to
adverse economic, political or regulatory developments than is a portfolio that
invests more broadly.

Investments in the Trust are subject to possible loss due to the financial
failure of the issuers of the underlying securities and the issuers' inability
to meet their debt obligations.

The Trust may invest up to 20% of its total assets in illiquid securities.
Illiquid securities may be difficult to dispose of at a price reflective of
their value at the times when the Trust believes it is desirable to do so, and
the market price of illiquid securities is generally more volatile than that of
more liquid securities. Illiquid securities are also more difficult to value and
investment of the Trust's assets in illiquid securities may restrict the Trust's
ability to take advantage of market opportunities.

The Trust uses leverage through the issuance of preferred shares. Leverage
creates significant risks, including the risk that the Trust's incremental
income or capital appreciation for investments purchased with the proceeds of
leverage will not be sufficient to cover the cost of the leverage, which may
adversely affect the return for the holders of common shares. Since February of
2008, regularly scheduled auctions for the Trust's preferred shares have failed
and preferred shareowners have not been able to sell their shares at auction.
The Board of Trustees of the Trust has considered, and continues to consider,
this issue.

The Trust is required to maintain certain regulatory rating agency and other
asset coverage requirements in connection with its outstanding preferred shares.
In order to maintain required asset coverage levels, the Trust may be required
to alter the composition of its investment portfolio or take other actions, such
as redeeming preferred shares with the proceeds from portfolio transactions, at
what might be inopportune times in the market. Such actions could reduce the net
earnings or returns to holders of the Trust's common shares over time.

8 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


Risks of investing in the Trust are discussed in greater detail in the Trust's
original offering prospectus and in shareowner reports issued from time to time.

These risks may increase share price volatility.

Any information in this shareholder report regarding market or economic trends
or the factors influencing the Fund's historical or future performance are
statements of opinion as of the date of this report. These statements should not
be relied upon for any other purposes. Past performance is no guarantee of
future results, and there is no guarantee that market forecasts discussed will
be realized.

            Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 9


Portfolio Summary | 10/31/14

Portfolio Diversification
--------------------------------------------------------------------------------
(As a percentage of total investment portfolio)

[THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL]



                                                          
Other Revenue                                                18.8%
Health Revenue                                               17.3%
Insured                                                      15.1%
Facilities Revenue                                           12.5%
Development Revenue                                          11.3%
Education Revenue                                             8.9%
Tobacco Revenue                                               7.2%
Transportation Revenue                                        4.2%
Airport Revenue                                               2.1%
Pollution Control Revenue                                     1.3%
Water Revenue                                                 1.3%
Utilities Revenue                                             0.0%*


*Amount rounds to less than 0.1%

10 Largest Holdings
--------------------------------------------------------------------------------
(As a percentage of long-term holdings)*



                                                                                           
  1.   Metropolitan Pier & Exposition Authority Dedicated State Tax Revenue, 6/15/22          4.44%
---------------------------------------------------------------------------------------------------
  2.   State of Washington, General Obligation, 6/1/22                                        3.15
---------------------------------------------------------------------------------------------------
  3.   Lehman Municipal Trust Receipts Revenue, 0.0%, 8/21/35                                 3.14
---------------------------------------------------------------------------------------------------
  4.   North Texas Tollway Authority Transportation Revenue, 5.75%, 1/1/33                    2.85
---------------------------------------------------------------------------------------------------
  5.   Lehman Municipal Trust Receipts Revenue, RIB, 0.0%, 9/20/28 (144A)                     2.66
---------------------------------------------------------------------------------------------------
  6.   Massachusetts Development Finance Agency Revenue, 5.75%, 1/1/42                        2.32
---------------------------------------------------------------------------------------------------
  7.   New York State Dormitory Authority Revenue, 0.0%, 5/29/14 (144A)                       2.26
---------------------------------------------------------------------------------------------------
  8.   New York State Dormitory Authority Revenue, 5.0%, 3/15/39                              2.20
---------------------------------------------------------------------------------------------------
  9.   State of Texas, General Obligation, 0.0%, 4/1/30                                       1.92
---------------------------------------------------------------------------------------------------
 10.   District of Columbia Tobacco Settlement Financing Corp., 6.75%, 5/15/40                1.54
---------------------------------------------------------------------------------------------------


* This list excludes temporary cash investments and derivative instruments. The
  portfolio is actively managed, and current holdings may be different. The
  holdings listed should not be considered recommendations to buy or sell any
  security listed.

10 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


Prices and Distributions | 10/31/14

Market Value per Common Share
--------------------------------------------------------------------------------



--------------------------------------------------------------------------------
                                       10/31/14                     4/30/14
--------------------------------------------------------------------------------
                                                              
        Market Value                    $15.26                      $14.90
--------------------------------------------------------------------------------
        Premium                         13.0%                       11.8%
--------------------------------------------------------------------------------


Net Asset Value per Common Share
--------------------------------------------------------------------------------



--------------------------------------------------------------------------------
                                      10/31/14                     4/30/14
--------------------------------------------------------------------------------
                                                             
       Net Asset Value                 $13.50                      $13.33
--------------------------------------------------------------------------------


Distributions per Common Share*
--------------------------------------------------------------------------------



--------------------------------------------------------------------------------
                                                Short-Term         Long-Term
                              Dividends        Capital Gains      Capital Gains
--------------------------------------------------------------------------------
                                                             
    5/1/14 - 10/31/14          $0.57               $ --               $ --
--------------------------------------------------------------------------------


The data shown above represents past performance, which is no guarantee of
future results.

*   The amount of distributions made to shareholders during the period were in
    excess of the net investment income earned by the Trust during the period.
    The Trust has accumulated undistributed net investment income which is part
    of the Trust's NAV. A portion of the accumulated net investment income was
    distributed to shareowners during the period.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 11


Performance Update | 10/31/14

Investment Returns
--------------------------------------------------------------------------------
The mountain chart on the right shows the change in market value, including
reinvestment of dividends and distributions, of a $10,000 investment made in
common shares of Pioneer Municipal High Income Trust during the periods shown,
compared to that of the Barclays Municipal Bond Index and Barclays High Yield
Municipal Bond Index.



Average Annual Total Returns
(As of October 31, 2014)
--------------------------------------------------------------------------------
                                         Barclays
                             Barclays    High Yield
           Net               Municipal   Municipal
           Asset             Bond        Bond
           Value    Market   Index       Index
Period     (NAV)    Price    (NAV)       (NAV)
--------------------------------------------------------------------------------
                             
10 Years    6.49%    8.18%   4.71%        5.62%
5 Years     8.84    11.48    5.26         8.26
1 Year     12.03    15.59    7.82        10.84
--------------------------------------------------------------------------------


[THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL]

Market Value of $10,000 Investment



                   Pioneer Municipal   Barclays Municipal   Barclays High Yield
                   High Income Trust   Bond Index           Municipal Bond Index
                                                      
10/31/2004         $10,000             $ 10,000             $ 10,000
10/31/2005         $10,721             $ 10,254             $ 10,941
10/31/2006         $11,416             $ 10,843             $ 12,239
10/31/2007         $12,176             $ 11,158             $ 12,516
10/31/2008         $ 8,440             $ 10,790             $ 10,147
10/31/2009         $12,753             $ 12,257             $ 11,623
10/31/2010         $15,747             $ 13,210             $ 13,234
10/31/2011         $16,226             $ 13,710             $ 13,678
10/31/2012         $19,669             $ 14,948             $ 15,994
10/31/2013         $18,999             $ 14,691             $ 15,592
10/31/2014         $21,960             $ 15,839             $ 17,282


Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent
month-end performance results. Current performance may be lower or higher than
the performance data quoted.

Performance data shown represents past performance. Past performance is no
guarantee of future results. Investment return and market price will fluctuate,
and your shares may trade below NAV due to such factors as interest rate changes
and the perceived credit quality of borrowers.

Total investment return does not reflect broker sales charges or commissions.
All performance is for common shares of the Trust.

Shares of closed-end funds, unlike open-end funds, are not continuously offered.
There is a one-time public offering and, once issued, shares of closed-end funds
are bought and sold in the open market through a stock exchange and frequently
trade at prices lower than their NAV. NAV per common share is total assets less
total liabilities, which include preferred shares or borrowings, as applicable,
divided by the number of common shares outstanding.

When NAV is lower than market price, dividends are assumed to be reinvested at
the greater of NAV or 95% of the market price. When NAV is higher, dividends are
assumed to be reinvested at prices obtained through open-market purchases under
the Trust's dividend reinvestment plan.

The performance table and graph do not reflect the deduction of fees and taxes
that a shareowner would pay on Trust distributions or the sale of Trust shares.
Had these fees and taxes been reflected, performance would have been lower.

The Barclays Municipal Bond Index is an unmanaged, broad measure of the
municipal bond market. The Barclays High Yield Municipal Bond Index is
unmanaged, totals over $26 billion in market value and maintains over 1300
securities. Municipal bonds in this index have the following requirements:
maturities of one year or greater, sub investment grade (below Baa or
non-rated), fixed coupon rate, issued after 12/31/90, deal size over $20
million, and maturity size of at least $3 million. Index returns are calculated
monthly, assume reinvestment of dividends and, unlike Trust returns, do not
reflect any fees, expenses or sales charges. The indices do not use leverage. It
is not possible to invest directly in the indices.

12 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


Schedule of Investments | 10/31/14 (unaudited)



---------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                              Value
---------------------------------------------------------------------------------------------------
                                                                               
                          TAX EXEMPT OBLIGATIONS -- 127.0% of
                          Net Assets
                          Alabama -- 1.5%
    4,500,000             Huntsville-Redstone Village Special Care Facilities
                          Financing Authority Nursing Home Revenue,
                          5.5%, 1/1/43                                               $    4,502,340
---------------------------------------------------------------------------------------------------
                          Arizona -- 0.0%+
       24,000             Pima County Industrial Development Authority
                          Education Revenue, 6.75%, 7/1/31                           $       24,038
---------------------------------------------------------------------------------------------------
                          California -- 10.8%
    3,000,000(a)          Abag Finance Authority for Nonprofit Corp., Revenue,
                          5.75%, 7/1/37                                              $    3,171,000
    1,450,000             California Enterprise Development Authority Recovery Zone
                          Facility Revenue, 8.5%, 4/1/31                                  1,677,664
    1,000,000             California Municipal Finance Authority, 5.75%, 7/1/30           1,042,670
    5,000,000             California Pollution Control Financing Authority, 5.0%,
                          7/1/37 (144A)                                                   5,168,500
    1,740,000             California School Finance Authority, 7.375%, 10/1/43            1,998,146
    1,400,000             California Statewide Communities Development Authority,
                          5.625%, 11/1/33                                                 1,483,608
      568,006(b)(c)       California Statewide Communities Development Authority
                          Environmental Facilities Revenue, 9.0%, 12/1/38                         6
   20,000,000(d)          Inland Empire Tobacco Securitization Authority Revenue,
                          6/1/36                                                          4,078,600
    7,885,000(e)          Lehman Municipal Trust Receipts Revenue, RIB, 0.0%,
                          9/20/28 (144A)                                                 10,387,857
    2,000,000             Tobacco Securitization Authority of Northern California
                          Revenue, 5.375%, 6/1/38                                         1,641,100
    3,000,000             Tobacco Securitization Authority of Southern California
                          Revenue, 5.0%, 6/1/37                                           2,395,740
                                                                                     --------------
                                                                                     $   33,044,891
---------------------------------------------------------------------------------------------------
                          Colorado -- 1.5%
    1,500,000             Colorado Educational & Cultural Facilities Authority,
                          8.0%, 9/1/43                                               $    1,537,845
    2,000,000             Colorado Health Facilities Authority Revenue,
                          5.25%, 5/15/42                                                  2,151,860
    1,000,000             Kremmling Memorial Hospital District Certificate of
                          Participation, 7.125%, 12/1/45                                    830,780
                                                                                     --------------
                                                                                     $    4,520,485
---------------------------------------------------------------------------------------------------
                          Connecticut -- 7.7%
    1,000,000             Hamden Connecticut Facility Revenue, 7.75%, 1/1/43         $    1,023,660
   10,335,000(e)          Lehman Municipal Trust Receipts Revenue, 0.0%, 8/21/35         12,272,813
    5,000,000             Mohegan Tribe of Indians Gaming Authority, 6.25%, 1/1/31        4,992,900
    5,000,000             State of Connecticut, General Obligation, 4.0%, 9/1/30          5,387,550
                                                                                     --------------
                                                                                     $   23,676,923
---------------------------------------------------------------------------------------------------


The accompanying notes are an integral part of these financial statements.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 13


Schedule of Investments | 10/31/14 (unaudited) (continued)



---------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                              Value
---------------------------------------------------------------------------------------------------
                                                                               
                          District of Columbia -- 3.8%
    5,000,000             District of Columbia Tobacco Settlement Financing
                          Corp., 6.5%, 5/15/33                                       $    5,749,050
    6,000,000             District of Columbia Tobacco Settlement Financing Corp.,
                          6.75%, 5/15/40                                                  5,999,100
                                                                                     --------------
                                                                                     $   11,748,150
---------------------------------------------------------------------------------------------------
                          Florida -- 6.5%
    1,500,000             Alachua County Health Facilities Authority Revenue,
                          8.125%, 11/15/41                                           $    1,731,465
    1,500,000             Alachua County Health Facilities Authority Revenue,
                          8.125%, 11/15/46                                                1,729,365
      500,000             Capital Trust Agency Revenue Bonds, 7.75%, 1/1/41                 509,945
    5,000,000             Florida's Turnpike Enterprise, 4.0%, 7/1/34                     5,236,800
    1,000,000(a)          Hillsborough County Industrial Development Authority
                          Revenue, 8.0%, 8/15/32                                          1,319,890
    2,260,000(b)          Liberty County Subordinate Revenue, 8.25%, 7/1/28                 498,330
    2,500,000             Miami-Dade County Florida Aviation Revenue,
                          5.5%, 10/1/41                                                   2,855,175
    2,250,000(e)          St. Johns County Industrial Development Authority
                          Revenue, 1.344%, 1/1/49                                           857,205
      832,581(b)          St. Johns County Industrial Development Authority
                          Revenue, 2.5%, 1/1/49                                                   8
    5,000,000             Tallahassee Health Facilities Revenue, 6.375%, 12/1/30          5,018,600
                                                                                     --------------
                                                                                     $   19,756,783
---------------------------------------------------------------------------------------------------
                          Georgia -- 5.1%
    4,240,000(e)          Atlanta Georgia Water and Wastewater Revenue, RIB, 0.0%,
                          11/1/43 (144A)                                             $    4,276,591
    2,500,000             Clayton County Development Authority Revenue, 8.75%,
                          6/1/29                                                          3,122,875
    3,445,000             Clayton County Development Authority Revenue,
                          9.0%, 6/1/35                                                    3,568,400
    4,000,000             Private Colleges & Universities Authority Revenue, 5.0%,
                          10/1/43                                                         4,561,240
                                                                                     --------------
                                                                                     $   15,529,106
---------------------------------------------------------------------------------------------------
                          Idaho -- 1.6%
    5,000,000             Power County Industrial Development Corp., Revenue,
                          6.45%, 8/1/32                                              $    5,009,350
---------------------------------------------------------------------------------------------------
                         Illinois -- 14.8%
    1,827,000(d)         Illinois Finance Authority Revenue, 11/15/52                $      160,335
    2,087,000(e)         Illinois Finance Authority Revenue, 4.0%, 11/15/52               1,352,501
    3,865,000            Illinois Finance Authority Revenue, 6.0%, 8/15/38                4,359,411
    2,000,000            Illinois Finance Authority Revenue, 6.0%, 8/15/39                2,348,540
      580,000            Illinois Finance Authority Revenue, 6.375%, 5/15/17                580,777


The accompanying notes are an integral part of these financial statements.

14 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14




---------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                              Value
---------------------------------------------------------------------------------------------------
                                                                               
                          Illinois -- (continued)
    2,500,000             Illinois Finance Authority Revenue, 6.5%, 4/1/39           $    2,747,100
      240,000             Illinois Finance Authority Revenue, 7.0%, 11/15/17                240,055
      500,000             Illinois Finance Authority Revenue, 7.0%, 5/15/18                 500,665
    1,700,000             Illinois Finance Authority Revenue, 7.625%, 5/15/25             1,807,967
      600,000             Illinois Finance Authority Revenue, 7.75%, 5/15/30                626,196
    2,000,000             Illinois Finance Authority Revenue, 8.0%, 5/15/40               2,104,540
    3,200,000             Illinois Finance Authority Revenue, 8.0%, 5/15/46               3,351,424
    2,000,000             Illinois Finance Authority Revenue, 8.125%, 2/15/40             2,118,480
    3,000,000             Illinois Finance Authority Revenue, 8.25%, 5/15/45              2,133,720
    2,500,000             Illinois Finance Authority Revenue, 8.25%, 2/15/46              2,654,975
   16,880,000(d)          Metropolitan Pier & Exposition Authority Dedicated State
                          Tax Revenue, 0.0%, 6/15/22                                     17,316,854
    1,250,000             Southwestern Illinois Development Authority Revenue,
                          5.625%, 11/1/26                                                 1,004,413
                                                                                     --------------
                                                                                     $   45,407,953
---------------------------------------------------------------------------------------------------
                          Indiana -- 1.7%
      250,000             City of Carmel Indiana Nursing Home Revenue, 7.0%,
                          11/15/32                                                   $      273,415
      750,000             City of Carmel Indiana Nursing Home Revenue, 7.125%,
                          11/15/42                                                          816,623
      500,000             City of Carmel Indiana Nursing Home Revenue, 7.125%,
                          11/15/47                                                          542,740
    3,570,000             Vigo County Hospital Authority Revenue, 5.8%,
                          9/1/47 (144A)                                                   3,693,236
                                                                                     --------------
                                                                                     $    5,326,014
---------------------------------------------------------------------------------------------------
                          Kentucky -- 1.9%
    5,000,000             Kentucky Economic Development Finance Authority
                          Revenue, 6.375%, 6/1/40                                    $    5,778,000
---------------------------------------------------------------------------------------------------
                          Louisiana -- 3.1%
    2,260,000             Jefferson Parish Hospital Service District No. 2, 6.375%,
                          7/1/41                                                     $    2,513,233
    1,500,000             Louisiana Local Government Environmental Facilities &
                          Community Development Authority Revenue, 6.75%,
                          11/1/32                                                         1,679,460
    5,000,000             Louisiana Public Facilities Authority Revenue, 5.5%,
                          5/15/47                                                         5,260,750
                                                                                     --------------
                                                                                     $    9,453,443
---------------------------------------------------------------------------------------------------
                          Maine -- 1.9%
    1,500,000             Maine Health & Higher Educational Facilities Authority
                          Revenue, 7.5%, 7/1/32                                      $    1,775,535
    3,500,000             Maine Turnpike Authority Revenue, 5.0%, 7/1/42                  3,915,065
                                                                                     --------------
                                                                                     $    5,690,600
---------------------------------------------------------------------------------------------------


The accompanying notes are an integral part of these financial statements.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 15


Schedule of Investments | 10/31/14 (unaudited) (continued)



---------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                              Value
---------------------------------------------------------------------------------------------------
                                                                               
                          Maryland -- 0.5%
    1,500,000             Maryland Health & Higher Educational Facilities Authority
                          Revenue, 6.75%, 7/1/44                                     $    1,617,555
---------------------------------------------------------------------------------------------------
                          Massachusetts -- 5.5%
    7,100,000             Massachusetts Development Finance Agency Revenue,
                          5.75%, 1/1/42                                              $    9,038,371
    2,095,000             Massachusetts Development Finance Agency Revenue,
                          7.1%, 7/1/32                                                    2,096,488
      635,000             Massachusetts Educational Financing Authority Revenue,
                          6.0%, 1/1/28                                                      676,948
    4,500,000(b)(c)       Massachusetts Health & Educational Facilities Authority
                          Revenue, 6.5%, 1/15/38                                             11,700
    5,000,000             Massachusetts Health & Educational Facilities Authority
                          Revenue, 6.75%, 10/1/33                                         5,006,150
                                                                                     --------------
                                                                                     $   16,829,657
---------------------------------------------------------------------------------------------------
                          Michigan -- 3.3%
      895,000             Doctor Charles Drew Academy Certificate of Participation,
                          5.7%, 11/1/36                                              $      178,991
    2,000,000             Kent Hospital Finance Authority Revenue, 6.25%, 7/1/40          2,051,760
    2,640,000             Michigan State University Revenue, 5.0%, 8/15/41                2,997,113
    6,100,000             Michigan Tobacco Settlement Finance Authority Revenue,
                          6.0%, 6/1/48                                                    4,938,743
                                                                                     --------------
                                                                                     $   10,166,607
---------------------------------------------------------------------------------------------------
                          Minnesota -- 0.7%
    2,000,000             Port Authority of the City of Bloomington, Minnesota
                          Recovery Zone Facility Revenue, 9.0%, 12/1/35              $    2,274,400
---------------------------------------------------------------------------------------------------
                          Montana -- 0.0%+
    1,600,000(b)(c)       Two Rivers Authority Inc., Project Revenue,
                          7.375%, 11/1/27                                            $      126,768
---------------------------------------------------------------------------------------------------
                          New Jersey -- 1.9%
    3,000,000             New Jersey Economic Development Authority Revenue,
                          5.25%, 9/15/29                                             $    3,179,880
    2,500,000             New Jersey Economic Development Authority Revenue,
                          5.75%, 9/15/27                                                  2,615,325
                                                                                     --------------
                                                                                     $    5,795,205
---------------------------------------------------------------------------------------------------
                          New Mexico -- 1.3%
    1,500,000             Otero County New Mexico Project Revenue, 6.0%, 4/1/23      $    1,357,410
    2,960,000             Otero County New Mexico Project Revenue, 6.0%, 4/1/28           2,508,718
                                                                                     --------------
                                                                                     $    3,866,128
---------------------------------------------------------------------------------------------------


The accompanying notes are an integral part of these financial statements.

16 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14




---------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                              Value
---------------------------------------------------------------------------------------------------
                                                                               
                          New York -- 9.7%
    2,000,000             Chautauqua County Capital Resource Corp., Revenue,
                          8.0%, 11/15/30                                             $    2,094,340
    2,000,000             Hempstead Local Development Corp., Revenue, 5.75%,
                          7/1/39                                                          2,173,240
    2,000,000             New York City Industrial Development Agency Revenue,
                          5.25%, 12/1/32                                                  2,000,040
    2,000,000             New York City Industrial Development Agency Revenue,
                          7.625%, 12/1/32                                                 2,010,900
    7,040,000(e)          New York State Dormitory Authority Revenue, 0.0%,
                          5/29/14 (144A)                                                  8,819,853
    7,500,000             New York State Dormitory Authority Revenue,
                          5.0%, 3/15/39                                                   8,572,350
    1,000,000             New York State Dormitory Authority Revenue, 6.125%,
                          12/1/29                                                         1,071,890
    2,577,540             Westchester County Healthcare Corp., Revenue, 5.0%,
                          11/1/44                                                         2,857,718
                                                                                     --------------
                                                                                     $   29,600,331
---------------------------------------------------------------------------------------------------
                          North Dakota -- 0.9%
    2,525,000             County of Burleigh ND, 5.0%, 7/1/38                        $    2,702,205
---------------------------------------------------------------------------------------------------
                          Ohio -- 1.8%
    2,500,000             Buckeye Tobacco Settlement Financing Authority Revenue,
                          5.875%, 6/1/47                                             $    1,974,900
    1,700,000             Buckeye Tobacco Settlement Financing Authority Revenue,
                          6.0%, 6/1/42                                                    1,339,243
    2,000,000(e)          Ohio Air Quality Development Authority Revenue, 3.1%,
                          3/1/23                                                          2,030,980
                                                                                     --------------
                                                                                     $    5,345,123
---------------------------------------------------------------------------------------------------
                          Oregon -- 1.9%
    5,190,000             Oregon Health & Science University Revenue, 5.0%,
                          7/1/32                                                     $    5,949,557
---------------------------------------------------------------------------------------------------
                          Pennsylvania -- 5.9%
    1,550,000             Allegheny County Hospital Development Authority
                          Revenue, 5.125%, 5/1/25                                    $    1,561,919
    1,280,000(b)(c)       Langhorne Manor Borough Higher Education Authority
                          Revenue, 7.35%, 7/1/22                                            377,600
    5,000,000             Pennsylvania Economic Development Financing Authority
                          Solid Waste Disposal Revenue, 6.0%, 6/1/31                      5,008,850
    1,000,000             Philadelphia Authority for Industrial Development Revenue,
                          6.5%, 6/15/33 (144A)                                            1,026,830
    2,000,000             Philadelphia Authority for Industrial Development Revenue,
                          6.75%, 6/15/43 (144A)                                           2,058,040
    2,000,000             Philadelphia Authority for Industrial Development Revenue,
                          8.2%, 12/1/43                                                   2,149,640


The accompanying notes are an integral part of these financial statements.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 17


Schedule of Investments | 10/31/14 (unaudited) (continued)



---------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                              Value
---------------------------------------------------------------------------------------------------
                                                                               
                          Pennsylvania -- (continued)
    5,900,000             Philadelphia Hospitals & Higher Education Facilities
                          Authority Revenue, 5.0%, 7/1/34                            $    5,939,117
                                                                                     --------------
                                                                                     $   18,121,996
---------------------------------------------------------------------------------------------------
                          Puerto Rico -- 0.9%
    3,255,000             Commonwealth of Puerto Rico, General Obligation, 8.0%,
                          7/1/35                                                     $    2,847,995
---------------------------------------------------------------------------------------------------
                          Rhode Island -- 1.6%
    5,900,000(b)(c)       Central Falls Rhode Island Detention Facility Corp.,
                          Revenue, 7.25%, 7/15/35                                    $    3,231,312
    1,500,000             Rhode Island Health & Educational Building Corp.,
                          Revenue, 8.375%, 1/1/46                                         1,728,705
                                                                                     --------------
                                                                                     $    4,960,017
---------------------------------------------------------------------------------------------------
                          Tennessee -- 1.6%
    4,600,000             Sullivan County Health, Educational & Housing Facilities
                          Board Revenue, 5.25%, 9/1/36                               $    4,838,694
---------------------------------------------------------------------------------------------------
                          Texas -- 16.5%
    1,000,000             Arlington Higher Education Finance Corp., Revenue Bonds,
                          7.0%, 3/1/34                                               $    1,054,480
    2,500,000             Central Texas Regional Mobility Authority Revenue, 6.75%,
                          1/1/41                                                          2,943,200
    5,000,000             Goose Creek Consolidated Independent School District,
                          General Obligation, 4.0%, 2/15/26                               5,558,400
      725,078(b)(c)       Gulf Coast Industrial Development Authority Revenue,
                          7.0%, 12/1/36                                                           7
    3,750,000             Houston Airport System Special Facilities Revenue, 5.7%,
                          7/15/29                                                         3,759,000
    5,340,000             Lubbock Health Facilities Development Corp., Nursing
                          Home Revenue, 6.625%, 7/1/36                                    5,514,778
   10,000,000             North Texas Tollway Authority Transportation Revenue,
                          5.75%, 1/1/33                                                  11,131,800
    1,500,000             Red River Health Facilities Development Corp., Revenue,
                          8.0%, 11/15/41                                                  1,769,085
    4,000,000             Sanger Industrial Development Corp., Revenue,
                          8.0%, 7/1/38                                                    4,424,840
    7,040,000(e)          State of Texas, General Obligation, 0.0%, 4/1/30                7,496,826
    2,000,000             Tarrant County Cultural Education Facilities Finance Corp.,
                          Revenue, 8.0%, 11/15/34                                         2,334,300
    1,000,000             Tarrant County Cultural Education Facilities Finance Corp.,
                          Revenue, 8.125%, 11/15/39                                         957,330
    1,000,000             Tarrant County Cultural Education Facilities Finance Corp.,
                          Revenue, 8.25%, 11/15/44                                          963,520
    2,500,000             Travis County Health Facilities Development Corp.,
                          Revenue, 7.125%, 1/1/46                                         2,728,175
                                                                                     --------------
                                                                                     $   50,635,741
---------------------------------------------------------------------------------------------------


The accompanying notes are an integral part of these financial statements.

18 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14




---------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                              Value
---------------------------------------------------------------------------------------------------
                                                                               
                          Washington -- 7.5%
   14,315,000(d)          State of Washington, General Obligation, 6/1/22            $   12,297,587
    3,795,000             Washington State Health Care Facilities Authority Revenue,
                          6.0%, 1/1/33                                                    4,353,055
    1,150,000             Washington State Housing Finance Commission Revenue,
                          6.75%, 10/1/47                                                  1,232,098
    5,000,000             Washington State Housing Finance Committee Nonprofit
                          Revenue, 5.625%, 1/1/27                                         5,025,350
                                                                                     --------------
                                                                                     $   22,908,090
---------------------------------------------------------------------------------------------------
                          West Virginia -- 0.9%
    2,000,000             City of Philippi WV, 7.75%, 10/1/44                        $    2,009,160
      735,000             West Virginia Hospital Finance Authority Hospital Revenue,
                          9.125%, 10/1/41                                                   793,418
                                                                                     --------------
                                                                                     $    2,802,578
---------------------------------------------------------------------------------------------------
                          Wisconsin -- 2.7%
    5,000,000             Wisconsin Public Finance Authority Continuing Care
                          Retirement Community Revenue, 8.25%, 6/1/46                $    5,874,850
      535,000             Wisconsin State Public Finance Authority Revenue,
                          8.375%, 6/1/20                                                    536,712
    1,500,000             Wisconsin State Public Finance Authority Revenue,
                          8.625%, 6/1/47                                                  1,804,905
                                                                                     --------------
                                                                                     $    8,216,467
---------------------------------------------------------------------------------------------------
                          TOTAL TAX EXEMPT OBLIGATIONS
                          (Cost $361,504,720)                                        $  389,073,190
---------------------------------------------------------------------------------------------------
                          MUNICIPAL COLLATERALIZED DEBT
                          OBLIGATION -- 0.4% of Net Assets
   10,000,000(c)(e)       Non-Profit Preferred Funding Trust I, 0.0%,
                          9/15/37 (144A)                                             $    1,198,600
---------------------------------------------------------------------------------------------------
                          TOTAL MUNICIPAL COLLATERALIZED DEBT OBLIGATION
                          (Cost $10,000,000)                                         $    1,198,600
---------------------------------------------------------------------------------------------------
                          TOTAL INVESTMENTS IN SECURITIES -- 127.4%
                          (Cost $371,504,720) (f) (g)                                $  390,271,790
---------------------------------------------------------------------------------------------------
                          OTHER ASSETS AND LIABILITIES -- 5.6%                       $   17,171,482
---------------------------------------------------------------------------------------------------
                          PREFERRED SHARES AT REDEMPTION VALUE,
                          INCLUDING DIVIDENDS PAYABLE -- (33.0)%                     $ (101,000,649)
---------------------------------------------------------------------------------------------------
                          NET ASSETS APPLICABLE TO
                          COMMON SHAREOWNERS -- 100.0%                               $  306,442,623
===================================================================================================


+   Amount rounds to less than 0.1%.

The accompanying notes are an integral part of these financial statements.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 19


Schedule of Investments | 10/31/14 (unaudited) (continued)

(144A) Security is exempt from registration under Rule 144A of the Securities
       Act of 1933. Such securities may be resold normally to qualified
       institutional buyers in a transaction exempt from registration. At
       October 31, 2014, the value of these securities amounted to $36,629,507,
       or 12.0% of total net assets applicable to common shareowners.

RIB    Residual Interest Bond. The interest rate is subject to change
       periodically and inversely based upon prevailing market rates. The
       interest rate shown is the rate at October 31, 2014.

(a)    Prerefunded bonds have been collateralized by U.S. Treasury or U.S.
       Government Agency securities which are held in escrow to pay interest and
       principal on the tax exempt issue and to retire the bonds in full at the
       earliest refunding date.

(b)    Security is in default and is non income producing.

(c)    Indicates a security that has been deemed illiquid. As of October 31,
       2014 the aggregate cost of illiquid securities in the Trust's portfolio
       was $20,739,304. As of that date, the aggregate value of illiquid
       securities in the Trust's portfolio of $4,945,993 represented 1.6% of
       total net assets applicable to common shareowners.

(d)    Security issued with a zero coupon. Income is recognized through
       accretion of discount.

(e)    The interest rate is subject to change periodically. The interest rate
       shown is the rate at October 31, 2014.

(f)    The concentration of investments by type of obligation/ market sector is
       as follows:



                                                                     
       Insured                                                          15.1%
       Revenue Bonds:
        Other Revenue                                                   18.8
        Health Revenue                                                  17.3
        Facilities Revenue                                              12.5
        Development Revenue                                             11.3
        Education Revenue                                                8.9
        Tobacco Revenue                                                  7.2
        Transportation Revenue                                           4.2
        Airport Revenue                                                  2.1
        Pollution Control Revenue                                        1.3
        Water Revenue                                                    1.3
        Utilities Revenue                                                0.0*
                                                                       -----
                                                                       100.0%
                                                                       =====


*      Amount is less than 0.1%.

(g)    At October 31, 2014, the net unrealized appreciation on investments based
       on cost for federal tax purposes of $367,222,980 was as follows:



                                                                                
       Aggregate gross unrealized appreciation for all investments in
         which there is an excess of value over tax cost                           $ 45,986,194

       Aggregate gross unrealized depreciation for all investments in
         which there is an excess of tax cost over value                            (22,937,384)
                                                                                   ------------
       Net unrealized appreciation                                                 $ 23,048,810
                                                                                   ============


For financial reporting purposes net unrealized appreciation on investments was
18,767,070 and cost of investments aggregated $371,504,720.

Purchases and sales of securities (excluding temporary cash investments) for the
six months ended October 31, 2014 aggregated $35,478,502 and $35,224,888,
respectively.

The accompanying notes are an integral part of these financial statements.

20 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


Various inputs are used in determining the value of the Trust's investments.
These inputs are summarized in the three broad levels below.

    Level 1 -- quoted prices in active markets for identical securities.

    Level 2 -- other significant observable inputs (including quoted prices for
               similar securities, interest rates, prepayment speeds, credit
               risks, etc.). See Notes to Financial Statements -- Note 1A.

    Level 3 -- significant unobservable inputs (including the Trust's own
               assumptions in determining fair value of investments). See Notes
               to Financial Statements -- Note 1A.

Generally, equity securities are categorized as Level 1, fixed income securities
and senior loans are categorized as Level 2, and securities valued using fair
value methods (other than prices supplied by independent pricing services or
broker dealers) as Level 3. See Notes to Financial Statements -- Note 1A.

The following is a summary of the inputs used as of October 31, 2014, in valuing
the Trust's investments.



----------------------------------------------------------------------------------------------------------------
                                                Level 1         Level 2              Level 3            Total
----------------------------------------------------------------------------------------------------------------
                                                                                        
Tax Exempt Obligations                          $ --            $389,073,190         $ --           $389,073,190
Municipal Collateralized
   Debt Obligation                                --               1,198,600           --              1,198,600
-----------------------------------------------------------------------------------------------------------------
Total Investments in Securities                 $ --            $390,271,790         $ --           $390,271,790
=================================================================================================================


The following is a reconciliation of assets valued using significant
unobservable inputs (Level 3):



----------------------------------------------------------------------------------------------------------------------------
                                    Change in
              Balance     Realized  Unrealized                                 Accrued     Transfers   Transfers   Balance
              as of       gain      appreciation                               discounts/  in to       out of      as of
              4/30/14     (loss)(1) (depreciation)(2)  Purchases  Sales        premiums    Level 3*    Level 3*    10/31/14
----------------------------------------------------------------------------------------------------------------------------
                                                                                         
Tax Exempt
  Obligations $2,955,000  $339,303  $(156,198)         $ --       $(3,139,500) $1,395      $ --        $ --         $ --
----------------------------------------------------------------------------------------------------------------------------
Total         $2,955,000  $339,303  $(156,198)         $ --       $(3,139,500) $1,395      $ --        $ --         $ --
============================================================================================================================


*    Transfers are calculated on the beginning of period values. During the six
     months ended October 31, 2014, there were no transfers between Levels 1, 2
     and 3.

(1)  Realized gain (loss) on these securities is included in the realized gain
     (loss) from investments in the Statement of Operations.

(2)  Unrealized appreciation (depreciation) on these securities is included in
     the change in unrealized appreciation (depreciation) from investments in
     the Statement of Operations.

Net change in unrealized (depreciation) of Level 3 investments still held and
considered Level 3 at 10/31/14: $0.

The accompanying notes are an integral part of these financial statements.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 21


Statement of Assets and Liabilities | 10/31/14 (unaudited)



                                                                          
ASSETS:
  Investments in securities, at value (cost $371,504,720)                    $  390,271,790
  Cash                                                                            9,058,036
  Receivables --
    Investment securities sold                                                      640,000
    Interest receivable                                                           7,737,432
  Reinvestment of distributions                                                     112,834
  Prepaid expenses                                                                    3,290
--------------------------------------------------------------------------------------------
      Total assets                                                           $  407,823,382
============================================================================================
LIABILITIES:
  Payables --
    Trustees' fees                                                                      983
Due to affiliates                                                                   207,995
Administration fee payable                                                           68,437
Accrued expenses                                                                    102,695
--------------------------------------------------------------------------------------------
      Total liabilities                                                      $      380,110
============================================================================================
PREFERRED SHARES AT REDEMPTION VALUE:
  $25,000 liquidation value per share applicable to 4,040 shares,
    including dividends payable of $649                                         101,000,649
--------------------------------------------------------------------------------------------
NET ASSETS APPLICABLE TO COMMON SHAREOWNERS:
  Paid-in capital                                                            $  317,625,900
  Undistributed net investment income                                             4,444,804
  Accumulated net realized loss on investments                                  (34,395,151)
  Net unrealized appreciation on investments                                     18,767,070
--------------------------------------------------------------------------------------------
      Net assets applicable to common shareowners                            $  306,442,623
============================================================================================
NET ASSET VALUE PER COMMON SHARE:
  No par value (unlimited number of shares authorized)
    Based on $306,442,623 / 22,692,712 common shares                         $        13.50
============================================================================================


The accompanying notes are an integral part of these financial statements.

22 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


Statement of Operations (unaudited)

For the Six Months Ended 10/31/14



                                                                             
INVESTMENT INCOME:
  Interest                                                                         $12,369,053
----------------------------------------------------------------------------------------------
EXPENSES:
  Management fees                                               $1,225,486
  Administrative reimbursements                                     99,328
  Transfer agent fees and expenses                                  11,858
  Shareholder communication expenses                                 5,250
  Auction agent fees                                               127,433
  Custodian fees                                                     2,608
  Professional fees                                                 54,270
  Printing expenses                                                  8,081
  Trustees' fees                                                     5,189
  Pricing fees                                                      10,177
  Miscellaneous                                                     39,782
----------------------------------------------------------------------------------------------
     Total expenses                                                                $ 1,589,462
----------------------------------------------------------------------------------------------
         Net investment income                                                     $10,779,591
----------------------------------------------------------------------------------------------
REALIZED AND UNREALIZED GAIN ON INVESTMENTS:
  Net realized gain investments                                 $   44,150
  Change in net unrealized appreciation investments              6,068,009
----------------------------------------------------------------------------------------------
     Net gain on investments                                                       $ 6,112,159
----------------------------------------------------------------------------------------------
DISTRIBUTIONS TO PREFERRED SHAREOWNERS FROM
NET INVESTMENT INCOME:                                                             $   (63,766)
----------------------------------------------------------------------------------------------
  Net increase in net assets resulting from operations                             $16,827,984
==============================================================================================


The accompanying notes are an integral part of these financial statements.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 23


Statements of Changes in Net Assets



--------------------------------------------------------------------------------------------------
                                                                   Six Months
                                                                   Ended
                                                                   10/31/14          Year Ended
                                                                   (unaudited)       4/30/14
---------------------------------------------------------------------------------------------------
                                                                               
FROM OPERATIONS:
Net investment income                                              $  10,779,591     $  23,700,478
Net realized gain on investments                                          44,150            22,648
Change in net unrealized appreciation (depreciation)
  on investments                                                       6,068,009       (29,259,653)
Distributions to preferred shareowners from net
  investment income                                                      (63,766)         (146,534)
---------------------------------------------------------------------------------------------------
     Net increase (decrease) in net assets resulting
         from operations                                           $  16,827,984     $  (5,683,061)
---------------------------------------------------------------------------------------------------
DISTRIBUTIONS TO COMMON SHAREOWNERS:
Net investment income and previously undistributed
  net investment income ($0.57 and $1.14 per
     share, respectively)                                          $ (12,919,422)    $ (25,766,179)
---------------------------------------------------------------------------------------------------
     Total distributions to common shareowners                     $ (12,919,422)    $ (25,766,179)
---------------------------------------------------------------------------------------------------
FROM TRUST SHARE TRANSACTIONS:
Reinvestment of distributions                                      $     662,244     $   1,128,491
---------------------------------------------------------------------------------------------------
  Net increase in net assets applicable to common
     shareowners from Trust share transactions                     $     662,244     $   1,128,491
---------------------------------------------------------------------------------------------------
  Net increase (decrease) in net assets applicable to
     common shareowners                                            $   4,570,806     $ (30,320,749)
NET ASSETS APPLICABLE TO COMMON SHAREOWNERS:
Beginning of period                                                  301,871,817       332,192,566
---------------------------------------------------------------------------------------------------
End of period                                                      $ 306,442,623     $ 301,871,817
---------------------------------------------------------------------------------------------------
Undistributed net investment income                                $   4,444,804     $   6,648,401
===================================================================================================


The accompanying notes are an integral part of these financial statements.

24 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


Financial Highlights



------------------------------------------------------------------------------------------------------------------------------------
                                                               Six Months
                                                               Ended         Year        Year       Year        Year       Year
                                                               10/31/14      Ended       Ended      Ended       Ended      Ended
                                                               (unaudited)   4/30/14     4/30/13    4/30/12     4/30/11    4/30/10
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                         
Per Share Operating Performance
Net asset value, beginning of period                           $  13.33      $  14.72    $  14.12   $  13.00    $  13.86   $  11.18
------------------------------------------------------------------------------------------------------------------------------------
Increase (decrease) from investment operations: (a)
   Net investment income                                       $   0.48      $   1.05    $   1.14   $   1.03    $   1.12   $   1.17
   Net realized and unrealized gain (loss) on investments          0.26         (1.29)       0.61       1.30       (0.89)      2.50
------------------------------------------------------------------------------------------------------------------------------------
Distributions to preferred shareowners from:
   Net investment income                                       $  (0.00)(b)  $  (0.01)   $  (0.01)  $  (0.01)   $  (0.02)  $  (0.02)
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) from investment operations             $   0.74      $  (0.25)   $   1.74   $   2.32    $   0.21   $   3.65
------------------------------------------------------------------------------------------------------------------------------------
Distributions to common shareowners from:
   Net investment income and previously undistributed net
      investment income                                        $  (0.57)*    $  (1.14)*  $  (1.14)  $  (1.20)*  $  (1.07)  $  (0.97)
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) in net asset value                     $   0.17      $  (1.39)   $   0.60   $   1.12    $  (0.86)  $   2.68
------------------------------------------------------------------------------------------------------------------------------------
Net asset value, end of period (c)                             $  13.50      $  13.33    $  14.72   $  14.12    $  13.00   $  13.86
------------------------------------------------------------------------------------------------------------------------------------
Market value, end of period (c)                                $  15.26      $  14.90    $  16.02   $  15.49    $  13.40   $  14.34
====================================================================================================================================
Total return at market value (d)                                   6.53%         1.10%      11.48%     25.95%       1.04%     48.69%
Ratios to average net assets of common shareowners:
   Total expenses (e)                                              1.04%(f)      1.04%       1.03%      1.08%       1.12%      1.14%
   Net investment income before preferred share distributions      7.03%(f)      7.89%       7.84%      7.50%       8.26%      9.07%
   Preferred share distributions                                   0.04%(f)      0.05%       0.08%      0.08%       0.14%      0.16%
   Net investment income available to common shareowners           6.99%(f)      7.84%       7.76%      7.42%       8.12%      8.91%
Portfolio turnover                                                    9%           19%         10%        11%         10%        11%
Net assets of common shareowners, end of period (in thousands) $306,443      $301,872    $332,193   $317,631    $291,053   $308,456


The accompanying notes are an integral part of these financial statements.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 25


Financial Highlights (continued)



------------------------------------------------------------------------------------------------------------------------------------
                                                                     Six Months
                                                                     Ended        Year      Year      Year      Year       Year
                                                                     10/31/14     Ended     Ended     Ended     Ended      Ended
                                                                     (unaudited)  4/30/14   4/30/13   4/30/12   4/30/11    4/30/10
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                         
Preferred shares outstanding (in thousands)                          $101,001     $101,000  $101,000  $101,000  $101,000   $101,000
Asset coverage per preferred share, end of period                    $100,852     $ 99,721  $107,211  $103,623  $ 97,044   $101,351
Average market value per preferred share (g)                         $ 25,000     $ 25,000  $ 25,000  $ 25,000  $ 25,000   $ 25,000
Liquidation value, including dividends payable, per preferred share  $ 25,001     $ 25,001  $ 25,001  $ 25,001  $ 25,001   $ 25,001
====================================================================================================================================


*   The amount of distributions made to shareowners during the period were in
    excess of the net investment income earned by the Trust during the period.
    The Trust has accumulated undistributed net investment income which is part
    of the Trust's NAV. A portion of the accumulated net investment income was
    distributed to shareowners during the period.

(a) The per common share data presented above is based upon the average common
    shares outstanding for the periods presented.

(b) Amount rounds to less than $(0.005) per share.

(c) Net asset value and market value are published in Barron's on Saturday, The
    Wall Street Journal on Monday and The New York Times on Monday and Saturday.

(d) Total investment return is calculated assuming a purchase of common shares
    at the current market value on the first day and a sale at the current
    market value on the last day of the periods reported. Dividends and
    distributions, if any, are assumed for purposes of this calculation to be
    reinvested at prices obtained under the Trust's dividend reinvestment plan.
    Total investment return does not reflect brokerage commissions. Past
    performance is not a guarantee of future results.

(e) Expense ratios do not reflect the effect of distribution payments to
    preferred shareowners.

(f) Annualized.

(g) Market value is redemption value without an active market.

The accompanying notes are an integral part of these financial statements.

26 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


Notes to Financial Statements | 10/31/14 (unaudited)

1. Organization and Significant Accounting Policies

Pioneer Municipal High Income Trust (the Trust) was organized as a Delaware
statutory trust on March 13, 2003. Prior to commencing operations on July 21,
2003, the Trust had no operations other than matters relating to its
organization and registration as a diversified, closed-end management investment
company under the Investment Company Act of 1940, as amended. The investment
objective of the Trust is to seek a high level of current income exempt from
regular federal income tax, and the Trust may, as a secondary objective, also
seek capital appreciation to the extent that it is consistent with its primary
investment objective.

The Trust's financial statements have been prepared in conformity with U.S.
generally accepted accounting principles that require the management of the
Trust to, among other things, make estimates and assumptions that affect the
reported amounts of assets and liabilities, the disclosure of contingent assets
and liabilities at the date of the financial statements, and the reported
amounts of income, expenses and gain or loss on investments during the reporting
period. Actual results could differ from those estimates.

The following is a summary of significant accounting policies followed by the
Trust in the preparation of its financial statements, which are consistent with
those policies generally accepted in the investment company industry:

A.  Security Valuation

    Security transactions are recorded as of trade date. Fixed income securities
    are valued at prices supplied by independent pricing services, which
    consider such factors as market prices, market events, quotations from one
    or more brokers, Treasury spreads, yields, maturities and ratings.
    Valuations may be supplemented by dealers and other sources, as required.
    The values of interest rate swaps are determined by obtaining dealer
    quotations. Equity securities that have traded on an exchange are valued at
    the last sale price on the principal exchange where they are traded. Equity
    securities that have not traded on the date of valuation or securities for
    which sale prices are not available, generally are valued using the mean
    between the last bid and asked prices. Shares of money market mutual funds
    are valued at such funds' net asset value.

    Securities for which independent pricing services are unable to supply
    prices or for which market prices and/or quotations are not readily
    available, or are considered to be unreliable are valued by a fair valuation
    team comprised of certain personnel of Pioneer Investment Management, Inc.
    (PIM), the Trust's investment adviser, pursuant to procedures adopted by the
    Trust's Board of

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 27


    Trustees. PIM's fair valuation team uses fair value methods approved by the
    Valuation Committee of the Board of Trustees. PIM's valuation team is
    responsible for monitoring developments that may impact fair valued
    securities and for discussing and assessing fair value on an ongoing basis,
    and at least quarterly, with the Valuation Committee of the Board of
    Trustees.

    At October 31, 2014, there were no securities valued using fair value
    methods (other than securities valued using prices supplied by independent
    pricing services or broker-dealers).

B.  Investment Income and Transactions

    Dividend income is recorded on the ex-dividend date, except that certain
    dividends from foreign securities where the ex-dividend date may have passed
    are recorded as soon as the Trust becomes aware of the ex-dividend date in
    the exercise of reasonable diligence.

    Interest income, including interest or income bearing cash accounts, is
    recorded on an accrual basis. Discount and premium on debt securities are
    accreted or amortized, respectively, daily, into interest income on a
    yield-to-maturity basis with a corresponding increase or decrease in the
    cost basis of the security.

    Gains and losses on sales of investments are calculated on the identified
    cost method for both financial reporting and federal income tax purposes.

C.  Federal Income Taxes

    It is the Trust's policy to comply with the requirements of the Internal
    Revenue Code applicable to regulated investment companies and to distribute
    all of its taxable income and net realized capital gains, if any, to its
    shareowners. Therefore, no federal income tax provision is required. As of
    April 30, 2014, the Trust did not accrue any interest or penalties with
    respect to uncertain tax positions, which if applicable, would be recorded
    as an income tax expense in the Statement of Operations. Tax returns filed
    within the prior three years remain subject to examination by federal and
    state tax authorities.

    The amount and character of income and capital gain distributions to
    shareowners are determined in accordance with federal income tax rules,
    which may differ from U.S. generally accepted accounting principles.
    Distributions in excess of net investment income or net realized gains are
    temporary overdistributions for financial statement purposes resulting from
    differences in the recognition or classification of income or distributions
    for financial statement and tax purposes. Capital accounts within the
    financial statements are adjusted for permanent book/tax differences to
    reflect tax character, but are not adjusted for temporary differences.



28 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


    The tax character of distributions paid to shareowners during the year ended
    April 30, 2014 was as follows:



    ------------------------------------------------------------------------------------
                                                                                    2014
    ------------------------------------------------------------------------------------
                                                                         
    Distribution paid from:
    Tax exempt income                                                       $ 25,370,988
    Ordinary income                                                              541,725
    ------------------------------------------------------------------------------------
    Total taxable distribution                                              $ 25,912,713
    ====================================================================================


    The following shows the components of distributable earnings (losses) on
    a federal income tax basis at April 30, 2014:



    -------------------------------------------------------------------------------------
                                                                                    2014
    -------------------------------------------------------------------------------------
                                                                        
    Distributable earnings:
    Undistributed tax-exempt income                                         $  4,813,807
    Undistributed ordinary income                                                400,499
    Capital loss carryforward                                                (36,519,720)
    Post-October loss deferred                                                  (766,920)
    Dividends payable                                                               (306)
    Unrealized appreciation                                                   16,980,801
    -------------------------------------------------------------------------------------
    Total                                                                   $(15,091,839)
    =====================================================================================


    The difference between book-basis and tax-basis unrealized appreciation is
    primarily attributable to the difference between book and tax amortization
    methods for premiums and discounts on fixed income securities, the book/tax
    difference in accrual of income on securities in default, and other book and
    tax temporary differences.

D.  Automatic Dividend Reinvestment Plan

    All common shareowners whose shares are registered in their own names
    automatically participate in the Automatic Dividend Reinvestment Plan (the
    Plan), under which participants receive all dividends and capital gain
    distributions (collectively, dividends) in full and fractional common shares
    of the Trust in lieu of cash. Shareowners may elect not to participate in
    the Plan. Shareowners not participating in the Plan receive all dividends
    and capital gain distributions in cash. Participation in the Plan is
    completely voluntary and may be terminated or resumed at any time without
    penalty by notifying American Stock Transfer & Trust Company, the agent for
    shareowners in administering the Plan (the Plan Agent), in writing prior to
    any dividend record date; otherwise such termination or resumption will be
    effective with respect to any subsequently declared dividend or other
    distribution.

    If a shareowner's shares are held in the name of a brokerage firm, bank or
    other nominee, the shareowner can ask the firm or nominee to participate in
    the Plan on the shareowner's behalf. If the firm or nominee does not offer
    the

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 29


    Plan, dividends will be paid in cash to the shareowner of record. A firm
    or nominee may reinvest a shareowner's cash dividends in common shares of
    the Trust on terms that differ from the terms of the Plan.

    Whenever the Trust declares a dividend on common shares payable in cash,
    participants in the Plan will receive the equivalent in common shares
    acquired by the Plan Agent either (i) through receipt of additional unissued
    but authorized common shares from the Trust or (ii) by purchase of
    outstanding common shares on the New York Stock Exchange or elsewhere. If,
    on the payment date for any dividend, the net asset value per common share
    is equal to or less than the market price per share plus estimated brokerage
    trading fees (market premium), the Plan Agent will invest the dividend
    amount in newly issued common shares. The number of newly issued common
    shares to be credited to each account will be determined by dividing the
    dollar amount of the dividend by the net asset value per common share on the
    date the shares are issued, provided that the maximum discount from the then
    current market price per share on the date of issuance does not exceed 5%.
    If, on the payment date for any dividend, the net asset value per common
    share is greater than the market value (market discount), the Plan Agent
    will invest the dividend amount in common shares acquired in open-market
    purchases. There are no brokerage charges with respect to newly issued
    common shares. However, each participant will pay a pro rata share of
    brokerage trading fees incurred with respect to the Plan Agent's open-market
    purchases. Participating in the Plan does not relieve shareowners from any
    federal, state or local taxes which may be due on dividends paid in any
    taxable year. Shareowners holding Plan shares in a brokerage account may not
    be able to transfer the shares to another broker and continue to participate
    in the Plan.

E.  Risks

    At times, the Trust's investments may represent industries or industry
    sectors that are interrelated or have common risks, making the Trust more
    susceptible to any economic, political, or regulatory developments or other
    risks affecting those industries and sectors. Information regarding the
    Trust's principal risks is contained in the Trust's original offering
    prospectus, with additional information included in the Trust's shareowner
    reports issued from time to time. Please refer to those documents when
    considering the Trust's principal risks.

    The Trust may invest in both investment grade and below investment grade
    (high-yield) municipal securities with a broad range of maturities and
    credit ratings. Debt securities rated below investment grade are commonly
    referred to as "junk bonds" and are considered speculative. Below investment
    grade

30 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


    securities involve greater risk of loss, are subject to greater price
    volatility, and are less liquid and more difficult to value, especially
    during periods of economic uncertainty or change, than higher rated debt
    securities.

2. Management Agreement

PIM, the Trust's investment adviser, a wholly owned indirect subsidiary of
UniCredit S.p.A. (UniCredit), manages the Trust's portfolio. Management fees
payable under the Trust's Advisory Agreement with PIM are calculated daily at
the annual rate of 0.60% of the Trust's average daily managed assets. "Managed
assets" means (a) the total assets of the Trust, including any form of
investment leverage, minus (b) all accrued liabilities incurred in the normal
course of operations, which shall not include any liabilities or obligations
attributable to investment leverage obtained through (i) indebtedness of any
type (including, without limitation, borrowing through a credit facility or the
issuance of debt securities), (ii) the issuance of preferred stock or other
similar preference securities, and/or (iii) any other means. For the period
ended October 31, 2014, the net management fee was 0.60% of the Trust's average
daily managed assets, which was equivalent to 0.80% of the Trust's average daily
net assets attributable to the common shareowners.

In addition, under PIM's management and administration agreements, certain other
services and costs are paid by PIM and reimbursed by the Trust. At October 31,
2014, $276,432 was payable to PIM related to management costs, administrative
costs and certain other services is included in "Due to Affiliates" and
"Administration fees payable" on the Statement of Assets and Liabilities.

3. Transfer Agents

Pioneer Investment Management Shareholder Services, Inc. (PIMSS), a wholly owned
indirect subsidiary of UniCredit, through a sub-transfer agency agreement with
American Stock Transfer & Trust Company, provides substantially all transfer
agent and shareowner services related to the Trust's common shares at negotiated
rates.

In addition, the Trust reimburses PIMSS for out-of-pocket expenses incurred by
PIMSS related to shareowner communications activities such as proxy and
statement mailings and outgoing phone calls.

4. Expense Offset Arrangement

The Trust has entered into an arrangement with its custodian whereby credits
realized as a result of uninvested cash balances are used to reduce a portion of
the Trust's custodian expenses. For the period ended October 31, 2014, the Trust
expenses were not reduced under such arrangement.



           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 31

5. Trust Shares

There are an unlimited number of common shares of beneficial interest
authorized.

Transactions in common shares of beneficial interest for the six months ended
October 31, 2014 and the year ended April 30, 2014 were as follows:



---------------------------------------------------------------------------------------
                                                        10/31/14               4/30/14
---------------------------------------------------------------------------------------
                                                                      
Shares outstanding at beginning of period             22,646,773            22,564,036
Reinvestment of distributions                             45,939                82,737
---------------------------------------------------------------------------------------
Shares outstanding at end of period                   22,692,712            22,646,773
=======================================================================================


The Trust may classify or reclassify any unissued shares of beneficial interest
into one or more series of preferred shares of beneficial interest. As of
October 31, 2014, there were 4,040 APS as follows: Series A -- 2,000 and Series
B -- 2,040.

Dividends on Series A and Series B are cumulative at a rate which is to be reset
every seven days based on the results of an auction. An auction fails if there
are more APS offered for sale than there are buyers. When an auction fails, the
dividend rate for the period will be the maximum rate on the auction dates
described in the prospectus for the APS. Preferred shareowners are not able to
sell their APS at an auction if the auction fails. Since February 2008, the
Trust's auctions related to the APS have failed. The maximum rate for each
series is 125% of the 7 day commercial paper rate or adjusted Kenny rate.
Dividend rates on APS ranged from 0.075% to 0.261% during the period ended
October 31, 2014.

The Trust is required to maintain asset coverage of at least 200% with respect
to all outstanding APS under the 1940 Act and the prospectus for the APS. The
Trust may not declare dividends or make other distributions on its common shares
or purchase any such shares if, at the time of the declaration, distribution or
purchase, the Trust does not comply with the asset coverage ratio described
above.

The APS are redeemable at the option of the Trust, in whole or in part, on any
dividend payment date at $25,000 per share plus any accumulated or unpaid
dividends, whether or not declared. The APS are also subject to mandatory
redemption at $25,000 per share plus any accumulated or unpaid dividends,
whether or not declared, if certain requirements relating to the composition of
the assets and liabilities of the Trust as set forth in the Statement of
Preferences are not satisfied.

The holders of APS have voting rights equal to the holders of the Trust's common
shares (one vote per share) and will vote together with holders of the common
shares as a single class. Holders of APS are also entitled to elect two

32 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


of the Trust's Trustees. In addition, the Investment Company Act of 1940, as
amended, requires that along with approval by shareowners that might otherwise
be required, the approval of the holders of a majority of any outstanding
preferred shares, voting separately as a class, would be required to (a) adopt
any plan of reorganization that would adversely affect the preferred shares and
(b) take any action requiring a vote of security holders, including, among other
things, changes in the Trust's subclassification as a closed-end management
investment company or changes in its fundamental investment restrictions.

6. Subsequent Events

The Board of Trustees of the Trust declared on November 3, 2014 a monthly
dividend from undistributed and accumulated net investment income of $0.085 per
common share, payable November 28, 2014, to common shareowners of record on
November 17, 2014.

Subsequent to October 31, 2014, dividends declared and paid on preferred shares
totaled $16,569 in aggregate for the two outstanding preferred share series
through December 17, 2014.

7. Change in Independent Registered Public Accounting Firm

The Board of Trustees of the Trust, with the approval and recommendation of the
Audit Committee, appointed Deloitte & Touche LLP to serve as the Trust's
independent registered public accounting firm for the fiscal year ending April
30, 2015. Deloitte & Touche LLP replaces Ernst & Young LLP, which resigned as
the Trust's independent registered public accounting firm, effective upon
completion of the audit of the Trust's financial statements for the fiscal year
ended April 30, 2014.

During the periods that Ernst & Young LLP served as the Trust's independent
registered public accounting firm, including the Trust's fiscal years ending
April 30, 2014 and April 30, 2013, Ernst & Young LLP's reports on the financial
statements of the Trust have not contained an adverse opinion or disclaimer of
opinion and have not been qualified or modified as to uncertainty, audit scope
or accounting principles. Further, there have been no disagreement with Ernst &
Young LLP on any matter of accounting principles or practices, financial
statement disclosure, or auditing scope or procedure, which, if not resolved to
the satisfaction of Ernst & Young LLP would have caused Ernst & Young LLP to
make reference to the subject matter of the disagreement in connection with its
report on the financial statements. In addition, there have been no reportable
events of the kind described in Item 304(a)(1)(v) of Regulation S-K under the
Securities Exchange Act of 1934.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 33


ADDITIONAL INFORMATION (unaudited)

During the period ended October 31, 2014, there have been no material changes in
the Trust's investment objective or fundamental policies that have not been
approved by the shareowners. There have been no changes in the Trust's charter
or By-Laws that would delay or prevent a change in control of the Trust which
has not been approved by the shareowners. During the period, there have been no
changes in the principal risk factors associated with investment in the Trust.
There were no changes in the persons who are primarily responsible for the
day-to-day management of the Trust's portfolio.

Notice is hereby given in accordance with Section 23(c) of the Investment
Company Act of 1940 that the Trust may purchase, from time to time, its common
shares in the open market.

Results of Shareholder Meeting (unaudited)

At the annual meeting of shareowners held on September 23, 2014, shareowners of
Pioneer Municipal High Income Trust were asked to consider the proposal
described below. A report of the total votes cast by the Trust's shareholders
follows:

Proposal 1 -- To elect Class II Trustees.



--------------------------------------------------------------------------------
Nominee                                      For             Withheld
--------------------------------------------------------------------------------
                                                       
Benjamin M. Friedman                         19,947,909      645,441
Margaret B.W. Graham                         19,909,467      683,883
Kenneth J. Taubes                            20,004,485      588,865


34 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


Approval of Investment Advisory Agreement

Pioneer Investment Management, Inc. (PIM) serves as the investment adviser to
Pioneer Municipal High Income Trust (the Trust) pursuant to an investment
advisory agreement between PIM and the Trust. In order for PIM to remain the
investment adviser of the Trust, the Trustees of the Trust must determine
annually whether to renew the investment advisory agreement for the Trust.

The contract review process began in January 2014 as the Trustees of the Trust
agreed on, among other things, an overall approach and timeline for the process.
Contract review materials were provided to the Trustees in March 2014 and July
2014. Supplemental contract review materials were provided to the Trustees in
September 2014. In addition, the Trustees reviewed and discussed the Trust's
performance at regularly scheduled meetings throughout the year, and took into
account other information related to the Trust provided to the Trustees at
regularly scheduled meetings, in connection with the review of the Trust's
investment advisory agreement.

In March 2014, the Trustees, among other things, discussed the memorandum
provided by Trust counsel that summarized the legal standards and other
considerations that are relevant to the Trustees in their deliberations
regarding the renewal of the investment advisory agreement, and reviewed and
discussed the qualifications of the investment management teams, as well as the
level of investment by the Trust's portfolio managers in the Trust. In July
2014, the Trustees, among other things, reviewed the Trust's management fee and
total expense ratios, the financial statements of PIM and its parent companies,
the profitability analyses provided by PIM, and possible economies of scale. The
Trustees also reviewed the profitability of the institutional business of PIM
and PIM's affiliate, Pioneer Institutional Asset Management, Inc. (together with
PIM, "Pioneer"), as compared to that of PIM's fund management business, and
considered the differences between the fees and expenses of the Trust and the
fees and expenses of Pioneer's institutional accounts, as well as the different
services provided by PIM to the Trust and by Pioneer to the institutional
accounts. The Trustees further considered contract review materials in September
2014.

At a meeting held on September 16, 2014, based on their evaluation of the
information provided by PIM and third parties, the Trustees of the Trust,
including the Independent Trustees voting separately, unanimously approved the
renewal of the investment advisory agreement for another year. In

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 35


considering the renewal of the investment advisory agreement, the Trustees
considered various factors that they determined were relevant, including the
factors described below. In all quintile rankings referred to throughout this
disclosure, first quintile is most favorable to the Trust's shareowners. The
Trustees did not identify any single factor as the controlling factor in
determining to approve the renewal of the agreement.

Nature, Extent and Quality of Services

The Trustees considered the nature, extent and quality of the services that had
been provided by PIM to the Trust, taking into account the investment objective
and strategy of the Trust. The Trustees reviewed the terms of the investment
advisory agreement. The Trustees also reviewed PIM's investment approach for the
Trust and its research process. The Trustees considered the resources of PIM and
the personnel of PIM who provide investment management services to the Trust.
They also reviewed the amount of non-Trust assets managed by the portfolio
managers of the Trust. The Trustees considered the non-investment resources and
personnel of PIM involved in PIM's services to the Trust, including PIM's
compliance and legal resources and personnel. The Trustees noted the substantial
attention and high priority given by PIM's senior management to the Pioneer fund
complex.

The Trustees considered that PIM supervises and monitors the performance of the
Trust's service providers and provides the Trust with personnel (including Trust
officers) and other resources that are necessary for the Trust's business
management and operations. The Trustees also considered that, as administrator,
PIM is responsible for the administration of the Trust's business and other
affairs. The Trustees considered the fees paid to PIM for the provision of
administration services.

Based on these considerations, the Trustees concluded that the nature, extent
and quality of services that had been provided by PIM to the Trust were
satisfactory and consistent with the terms of the investment advisory agreement.

Performance of the Trust

In considering the Trust's performance, the Trustees regularly review and
discuss analysis and data prepared by PIM and information comparing the Trust's
performance with the performance of its peer group of funds as classified by
each of Morningstar, Inc. (Morningstar) and Lipper, and with the performance of
the Trust's benchmark index. They also discuss the Trust's performance with PIM
on a regular basis. The Trustees confirmed that these regular reviews and
discussions were factored into the Trustees' deliberations

36 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


concerning the renewal of the advisory agreement. For purposes of their contract
renewal deliberations, the Trustees considered the discussions held throughout
the year regarding the Trust's performance and the performance results of the
Trust over various time periods, including the Trust's performance results for
periods ended June 30, 2014. The Trustees indicated that they were satisfied
with PIM's response to the Trust's performance issues.

Management Fee and Expenses

The Trustees considered information showing the fees and expenses of the Trust
in comparison to the management fees and the expense ratios of a peer group of
funds selected on the basis of criteria determined by the Independent Trustees
for this purpose using data provided by Strategic Insight Mutual Fund Research
and Consulting, LLC (Strategic Insight), an independent third party.

The Trustees considered that the Trust's management fee (based on managed
assets) for the twelve months ended June 30, 2014 was in the third quintile
relative to the management fees paid by other funds in its Strategic Insight
peer group for the comparable period. The Trustees considered that the expense
ratio (based on managed assets) of the Trust's common shares for the twelve
months ended June 30, 2014 was in the third quintile relative its Strategic
Insight peer group for the comparable period.

The Trustees reviewed management fees charged by Pioneer to institutional and
other clients, including publicly offered European funds sponsored by affiliates
of Pioneer, unaffiliated U.S. registered investment companies (in a sub-advisory
capacity), and unaffiliated foreign and domestic separate accounts. The Trustees
also considered PIM's costs in providing services to the Trust and Pioneer's
costs in providing services to the other clients and considered the differences
in management fees and profit margins for Trust and non-Trust services. In
evaluating the fees associated with Pioneer's client accounts, the Trustees took
into account the respective demands, resources and complexity associated with
the Trust and client accounts. The Trustees noted that, in some instances, the
fee rates for those clients were lower than the management fee for the Trust and
considered that, under the investment advisory agreement with the Trust, PIM
performs additional services for the Trust that it does not provide to those
other clients or services that are broader in scope, including oversight of the
Trust's other service providers and activities related to compliance and the
extensive regulatory and tax regimes to which the Trust is subject. The Trustees
also considered the different entrepreneurial risks associated with PIM's
management of the Trust and Pioneer's management of the other client accounts.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 37


The Trustees concluded that the management fee payable by the Trust to PIM was
reasonable in relation to the nature and quality of the services provided by PIM
to the Trust.

Profitability

The Trustees considered information provided by PIM regarding the profitability
of PIM with respect to the advisory services provided by PIM to the Trust,
including the methodology used by PIM in allocating certain of its costs to the
management of the Trust. The Trustees also considered PIM's profit margin in
connection with the overall operation of the Trust. They further reviewed the
financial results realized by PIM and its affiliates from non-fund businesses.
The Trustees considered PIM's profit margins with respect to the Trust in
comparison to the limited industry data available and noted that the
profitability of any adviser was affected by numerous factors, including its
organizational structure and method for allocating expenses. The Trustees
concluded that PIM's profitability with respect to the management of the Trust
was not unreasonable.

Economies of Scale

The Trustees considered the extent to which PIM may realize economies of scale
or other efficiencies in managing and supporting the Trust. Since the Trust is a
closed-end fund that has not raised additional capital, the Trustees concluded
that economies of scale were not a relevant consideration in the renewal of the
investment advisory agreement.

Other Benefits

The Trustees considered the other benefits to PIM from its relationship with the
Trust. The Trustees considered the character and amount of fees paid by the
Trust, other than under the investment advisory agreement, for services provided
by PIM and its affiliates. The Trustees further considered the revenues and
profitability of PIM's businesses other than the fund business. Pioneer is the
principal U.S. asset management business of Pioneer Global Asset Management, the
worldwide asset management business of UniCredit Group, which manages over $150
billion in assets (including the Funds). Pioneer and the Funds receive
reciprocal intangible benefits from the relationship, including mutual brand
recognition and, for the Funds, direct and indirect access to the resources of a
large global asset manager. The Trustees concluded that any such benefits
received by Pioneer as a result of its

38 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


relationship with the Funds were reasonable and their consideration of the
advisory agreement between the Trust and PIM and the fees thereunder were
unaffected by Pioneer's possible receipt of any such intangible benefits.

Conclusion

After consideration of the factors described above as well as other factors, the
Trustees, including all of the Independent Trustees, concluded that the
investment advisory agreement between PIM and the Trust, including the fees
payable thereunder, was fair and reasonable and voted to approve the proposed
renewal of the investment advisory agreement for the Trust.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 39


Trustees, Officers and Service Providers

Trustees                                   Advisory Trustee
Thomas J. Perna, Chairman                  Lorraine H. Monchak*
David R. Bock
Benjamin M. Friedman                       Officers
Margaret B.W. Graham                       Lisa M. Jones, President and Chief
Marguerite A. Piret                          Executive Officer
Fred J. Ricciardi**                        Mark E. Bradley, Treasurer and
Kenneth J. Taubes                            Chief Financial Officer
                                           Christopher J. Kelley, Secretary and
                                           Chief Legal Officer

Investment Adviser and Administrator
Pioneer Investment Management, Inc.

Custodian and Sub-Administrator
Brown Brothers Harriman & Co.

Principal Underwriter
Pioneer Funds Distributor, Inc.

Legal Counsel
Morgan, Lewis & Bockius LLP

Shareowner Services and Transfer Agent
Pioneer Investment Management Shareholder Services, Inc.

Proxy Voting Policies and Procedures of the Fund are available without charge,
upon request, by calling our toll free number (1-800-225-6292). Information
regarding how the Fund voted proxies relating to portfolio securities during the
most recent 12-month period ended June 30 is publicly available to shareowners
at us.pioneerinvestments.com. This information is also available on the
Securities and Exchange Commission's web site at www.sec.gov.

*  Ms. Monchak became a non-voting Advisory Trustee on November 11, 2014.

** Mr. Ricciardi became a Trustee on November 11, 2014.

40 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


                           This page for your notes.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 41

                           This page for your notes.

42 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


                           This page for your notes.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14 43

                           This page for your notes.

44 Pioneer Municipal High Income Trust | Semiannual Report | 10/31/14


How to Contact Pioneer

We are pleased to offer a variety of convenient ways for you to contact us for
assistance or information.

You can call American Stock Transfer & Trust Company (AST) for:
---------------------------------------------------------------------------
Account Information                                  1-800-710-0935

Or write to AST:
--------------------------------------------------------------------------
For                                                  Write to

General inquiries, lost dividend checks,             American Stock
change of address, lost stock certificates,          Transfer & Trust
stock transfer                                       Operations Center
                                                     6201 15th Ave.
                                                     Brooklyn, NY 11219

Dividend reinvestment plan (DRIP)                    American Stock
                                                     Transfer & Trust
                                                     Wall Street Station
                                                     P.O. Box 922
                                                     New York, NY 10269-0560

Website www.amstock.com

For additional information, please contact your investment advisor or visit our
web site us.pioneerinvestments.com.

The Trust files a complete schedule of investments with the Securities and
Exchange Commission for the first and third quarters for each fiscal year on
Form N-Q. Shareowners may view the filed Form N-Q by visiting the Commission's
web site at www.sec.gov. The filed form may also be viewed and copied at the
Commission's Public Reference Room in Washington, DC. Information regarding the
operations of the Public Reference Room may be obtained by calling
1-800-SEC-0330.


[LOGO] PIONEER
       Investments(R)

Pioneer Investment Management, Inc.
60 State Street
Boston, MA 02109

us.pioneerinvestments.com

Securities offered through Pioneer Funds Distributor, Inc.
60 State Street, Boston, MA 02109
Underwriter of Pioneer Mutual Funds, Member SIPC
(C) 2014 Pioneer Investments 19442-08-1214



ITEM 2. CODE OF ETHICS.

(a) Disclose whether, as of the end of the period covered by the report, the
registrant has adopted a code of ethics that applies to the registrant's
principal executive officer, principal financial officer, principal accounting
officer or controller, or persons performing similar functions, regardless of
whether these individuals are employed by the registrant or a third party.  If
the registrant has not adopted such a code of ethics, explain why it has not
done so.

The registrant has adopted, as of the end of the period covered by this report,
a code of ethics that applies to the registrant's principal executive officer,
principal financial officer, principal accounting officer and controller.

(b) For purposes of this Item, the term "code of ethics" means written standards
that are reasonably designed to deter wrongdoing and to promote:

        (1) Honest and ethical conduct, including the ethical handling of actual
        or apparent conflicts of interest between personal and professional
        relationships;

        (2) Full, fair, accurate, timely, and understandable disclosure in
        reports and documents that a registrant files with, or submits to, the
        Commission and in other public communications made by the registrant;

        (3) Compliance with applicable governmental laws, rules, and
        regulations;

        (4) The prompt internal reporting of violations of the code to an
        appropriate person or persons identified in the code; and

        (5) Accountability for adherence to the code.

(c) The registrant must briefly describe the nature of any amendment, during the
period covered by the report, to a provision of its code of ethics that applies
to the registrant's principal executive officer, principal financial officer,
principal accounting officer or controller, or persons performing similar
functions, regardless of whether these individuals are employed by the
registrant or a third party, and that relates to any element of the code of
ethics definition enumerated in paragraph (b) of this Item. The registrant must
file a copy of any such amendment as an exhibit pursuant to Item 10(a), unless
the registrant has elected to satisfy paragraph (f) of this Item by posting its
code of ethics on its website pursuant to paragraph (f)(2) of this Item, or by
undertaking to provide its code of ethics to any person without charge, upon
request, pursuant to paragraph (f)(3) of this Item.

The registrant has made no amendments to the code of ethics during the period
covered by this report.

(d) If the registrant has, during the period covered by the report, granted a
waiver, including an implicit waiver, from a provision of the code of ethics to
the registrant's principal executive officer, principal financial officer,
principal accounting officer or controller, or persons performing similar
functions, regardless of whether these individuals are employed by the
registrant or a third party, that relates to one or more of the items set forth
in paragraph (b) of this Item, the registrant must briefly describe the nature
of the waiver, the name of the person to whom the waiver was granted, and the
date of the waiver.

Not applicable.

(e) If the registrant intends to satisfy the disclosure requirement under
paragraph (c) or (d) of this Item regarding an amendment to, or a waiver from,
a provision of its code of ethics that applies to the registrant's principal
executive officer, principal financial officer, principal accounting officer or
controller, or persons performing similar functions and that relates to any
element of the code of ethics definition enumerated in paragraph (b) of this
Item by posting such information on its Internet website, disclose the
registrant's Internet address and such intention.

Not applicable.

(f) The registrant must:

        (1) File with the Commission, pursuant to Item 12(a)(1), a copy of
        its code of ethics that applies to the registrant's principal
        executive officer,principal financial officer, principal accounting
        officer or controller, or persons performing similar functions,
        as an exhibit to its annual
        report on this Form N-CSR (see attachment);

        (2) Post the text of such code of ethics on its Internet website and
        disclose, in its most recent report on this Form N-CSR, its Internet
        address and the fact that it has posted such code of ethics on its
        Internet website; or

        (3) Undertake in its most recent report on this Form N-CSR to provide to
        any person without charge, upon request, a copy of such code of ethics
        and explain the manner in which such request may be made.
	See Item 10(2)

ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.

(a) (1)  Disclose that the registrant's board of trustees has determined that
         the registrant either:

    (i)  Has at least one audit committee financial expert serving on its audit
         committee; or

    (ii) Does not have an audit committee financial expert serving on its audit
         committee.

The registrant's Board of Trustees has determined that the registrant has at
least one audit committee financial expert.

    (2) If the registrant provides the disclosure required by paragraph
(a)(1)(i) of this Item, it must disclose the name of the audit committee
financial expert and whether that person is "independent." In order to be
considered "independent" for purposes of this Item, a member of an audit
committee may not, other than in his or her capacity as a member of the audit
committee, the board of trustees, or any other board committee:

    (i)  Accept directly or indirectly any consulting, advisory, or other
         compensatory fee from the issuer; or

    (ii) Be an "interested person" of the investment company as defined in
         Section 2(a)(19) of the Act (15 U.S.C. 80a-2(a)(19)).

Ms. Marguerite A. Piret, an independent trustee, is such an audit committee
financial expert.

    (3) If the registrant provides the disclosure required by paragraph (a)(1)
(ii) of this Item, it must explain why it does not have an audit committee
financial expert.

Not applicable.


ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.

(a) Disclose, under the caption AUDIT FEES, the aggregate fees billed for each
of the last two fiscal years for professional services rendered by the principal
accountant for the audit of the registrant's annual financial statements or
services that are normally provided by the accountant in connection with
statutory and regulatory filings or engagements for those fiscal years.

N/A

(b) Disclose, under the caption AUDIT-RELATED FEES, the aggregate fees billed in
each of the last two fiscal years for assurance and related services by the
principal accountant that are reasonably related to the performance of the audit
of the registrant's financial statements and are not reported under
paragraph (a) of this Item. Registrants shall describe the nature of the
services comprising the fees disclosed under this category.

N/A


(c) Disclose, under the caption TAX FEES, the aggregate fees billed in each of
the last two fiscal years for professional services rendered by the principal
accountant for tax compliance, tax advice, and tax planning. Registrants shall
describe the nature of the services comprising the fees disclosed under this
category.

N/A

(d) Disclose, under the caption ALL OTHER FEES, the aggregate fees billed in
each of the last two fiscal years for products and services provided by the
principal accountant, other than the services reported in paragraphs (a) through
(c) of this Item. Registrants shall describe the nature of the services
comprising the fees disclosed under this category.

N/A

(e) (1) Disclose the audit committee's pre-approval policies and procedures
described in paragraph (c)(7) of Rule 2-01 of Regulation S-X.

 PIONEER FUNDS
            APPROVAL OF AUDIT, AUDIT-RELATED, TAX AND OTHER SERVICES
                       PROVIDED BY THE INDEPENDENT AUDITOR

                  SECTION I - POLICY PURPOSE AND APPLICABILITY

The Pioneer Funds recognize the importance of maintaining the independence of
their outside auditors. Maintaining independence is a shared responsibility
involving Pioneer Investment Management, Inc ("PIM"), the audit committee and
the independent auditors.

The Funds recognize that a Fund's independent auditors: 1) possess knowledge of
the Funds, 2) are able to incorporate certain services into the scope of the
audit, thereby avoiding redundant work, cost and disruption of Fund personnel
and processes, and 3) have expertise that has value to the Funds. As a result,
there are situations where it is desirable to use the Fund's independent
auditors for services in addition to the annual audit and where the potential
for conflicts of interests are minimal. Consequently, this policy, which is
intended to comply with Rule 210.2-01(C)(7), sets forth guidelines and
procedures to be followed by the Funds when retaining the independent audit firm
to perform audit, audit-related tax and other services under those
circumstances, while also maintaining independence.

Approval of a service in accordance with this policy for a Fund shall also
constitute approval for any other Fund whose pre-approval is required pursuant
to Rule 210.2-01(c)(7)(ii).

In addition to the procedures set forth in this policy, any non-audit services
that may be provided consistently with Rule 210.2-01 may be approved by the
Audit Committee itself and any pre-approval that may be waived in accordance
with Rule 210.2-01(c)(7)(i)(C) is hereby waived.

Selection of a Fund's independent auditors and their compensation shall be
determined by the Audit Committee and shall not be subject to this policy.



                               SECTION II - POLICY

---------------- -------------------------------- -------------------------------------------------
SERVICE           SERVICE CATEGORY DESCRIPTION      SPECIFIC PRE-APPROVED SERVICE SUBCATEGORIES
CATEGORY
---------------- -------------------------------- -------------------------------------------------
                                            
I.  AUDIT        Services that are directly       o Accounting research assistance
SERVICES         related to performing the        o SEC consultation, registration
                 independent audit of the Funds     statements, and reporting
                                                  o Tax accrual related matters
                                                  o Implementation of new accounting
                                                    standards
                                                  o Compliance letters (e.g. rating agency
                                                    letters)
                                                  o Regulatory reviews and assistance
                                                    regarding financial matters
                                                  o Semi-annual reviews (if requested)
                                                  o Comfort letters for closed end
                                                    offerings
---------------- -------------------------------- -------------------------------------------------
II.              Services which are not           o AICPA attest and agreed-upon procedures
AUDIT-RELATED    prohibited under Rule            o Technology control assessments
SERVICES         210.2-01(C)(4) (the "Rule")      o Financial reporting control assessments
                 and are related extensions of    o Enterprise security architecture
                 the audit services support the     assessment
                 audit, or use the
                 knowledge/expertise gained
                 from the audit procedures as a
                 foundation to complete the
                 project.  In most cases, if
                 the Audit-Related Services are
                 not performed by the Audit
                 firm, the scope of the Audit
                 Services would likely
                 increase.  The Services are
                 typically well-defined and
                 governed by accounting
                 professional standards (AICPA,
                 SEC, etc.)
---------------- -------------------------------- -------------------------------------------------

 ------------------------------------- ------------------------------------
                                    
   AUDIT COMMITTEE APPROVAL POLICY               AUDIT COMMITTEE
                                                REPORTING POLICY
 ------------------------------------- ------------------------------------
                                    
 o "One-time" pre-approval             o A summary of all such
   for the audit period for all          services and related fees
   pre-approved specific service         reported at each regularly
   subcategories.  Approval of the       scheduled Audit Committee
   independent auditors as               meeting.
   auditors for a Fund shall
   constitute pre approval for
   these services.
 ------------------------------------- ------------------------------------
 o "One-time" pre-approval             o A summary of all such
   for the fund fiscal year within       services and related fees
   a specified dollar limit              (including comparison to
   for all pre-approved                  specified dollar limits)
   specific service subcategories        reported quarterly.

 o Specific approval is
   needed to exceed the
   pre-approved dollar limit for
   these services (see general
   Audit Committee approval policy
   below for details on obtaining
   specific approvals)

 o Specific approval is
   needed to use the Fund's
   auditors for Audit-Related
   Services not denoted as
   "pre-approved", or
   to add a specific service
   subcategory as "pre-approved"
 ------------------------------------- ------------------------------------




                     SECTION III - POLICY DETAIL, CONTINUED

----------------------- --------------------------- -----------------------------------------------
   SERVICE CATEGORY          SERVICE CATEGORY        SPECIFIC PRE-APPROVED SERVICE SUBCATEGORIES
                               DESCRIPTION
----------------------- --------------------------- -----------------------------------------------
                                              
III. TAX SERVICES       Services which are not      o Tax planning and support
                        prohibited by the Rule,     o Tax controversy assistance
                        if an officer of the Fund   o Tax compliance, tax returns, excise
                        determines that using the     tax returns and support
                        Fund's auditor to provide   o Tax opinions
                        these services creates
                        significant synergy in
                        the form of efficiency,
                        minimized disruption, or
                        the ability to maintain a
                        desired level of
                        confidentiality.
----------------------- --------------------------- -----------------------------------------------

------------------------------------- -------------------------
  AUDIT COMMITTEE APPROVAL POLICY         AUDIT COMMITTEE
                                          REPORTING POLICY
------------------------------------- -------------------------
------------------------------------- -------------------------
o "One-time" pre-approval             o A summary of
  for the fund fiscal  year             all such services and
  within a specified dollar limit       related fees
  				        (including comparison
  			                to specified dollar
  			                limits) reported
  			                quarterly.

o Specific approval is
  needed to exceed the
  pre-approved dollar limits for
  these services (see general
  Audit Committee approval policy
  below for details on obtaining
  specific approvals)

o Specific approval is
  needed to use the Fund's
  auditors for tax services not
  denoted as pre-approved, or to add a specific
  service subcategory as
  "pre-approved"
------------------------------------- -------------------------




                     SECTION III - POLICY DETAIL, CONTINUED

----------------------- --------------------------- -----------------------------------------------
   SERVICE CATEGORY          SERVICE CATEGORY        SPECIFIC PRE-APPROVED SERVICE SUBCATEGORIES
                               DESCRIPTION
----------------------- --------------------------- -----------------------------------------------
                                              
IV.  OTHER SERVICES     Services which are not      o Business Risk Management support
                        prohibited by the Rule,     o Other control and regulatory
A. SYNERGISTIC,         if an officer of the Fund     compliance projects
UNIQUE QUALIFICATIONS   determines that using the
                        Fund's auditor to provide
                        these services creates
                        significant synergy in
                        the form of efficiency,
                        minimized disruption,
                        the ability to maintain a
                        desired level of
                        confidentiality, or where
                        the Fund's auditors
                        posses unique or superior
                        qualifications to provide
                        these services, resulting
                        in superior value and
                        results for the Fund.
----------------------- --------------------------- -----------------------------------------------

--------------------------------------- ------------------------
    AUDIT COMMITTEE APPROVAL POLICY         AUDIT COMMITTEE
                                            REPORTING POLICY
------------------------------------- --------------------------
                                   
o "One-time" pre-approval             o A summary of
  for the fund fiscal year within       all such services and
  a specified dollar limit              related fees
  			               (including comparison
  			                to specified dollar
  				        limits) reported
                                        quarterly.
o Specific approval is
  needed to exceed the
  pre-approved dollar limits for
  these services (see general
  Audit Committee approval policy
  below for details on obtaining
  specific approvals)

o Specific approval is
  needed to use the Fund's
  auditors for "Synergistic" or
  "Unique Qualifications" Other
  Services not denoted as
  pre-approved to the left, or to
  add a specific service
  subcategory as "pre-approved"
------------------------------------- --------------------------




                     SECTION III - POLICY DETAIL, CONTINUED

----------------------- ------------------------- -----------------------------------------------
   SERVICE CATEGORY         SERVICE CATEGORY        SPECIFIC PROHIBITED SERVICE SUBCATEGORIES
                              DESCRIPTION
----------------------- ------------------------- -----------------------------------------------
                                            
PROHIBITED  SERVICES    Services which result     1. Bookkeeping or other services
                        in the auditors losing       related to the accounting records or
                        independence status          financial statements of the audit
                        under the Rule.              client*
                                                  2. Financial information systems design
                                                     and implementation*
                                                  3. Appraisal or valuation services,
                                                     fairness* opinions, or
                                                     contribution-in-kind reports
                                                  4. Actuarial services (i.e., setting
                                                     actuarial reserves versus actuarial
                                                     audit work)*
                                                  5. Internal audit outsourcing services*
                                                  6. Management functions or human
                                                     resources
                                                  7. Broker or dealer, investment
                                                     advisor, or investment banking services
                                                  8. Legal services and expert services
                                                     unrelated to the audit
                                                  9. Any other service that the Public
                                                     Company Accounting Oversight Board
                                                     determines, by regulation, is
                                                     impermissible
----------------------- ------------------------- -----------------------------------------------

------------------------------------------- ------------------------------
     AUDIT COMMITTEE APPROVAL POLICY               AUDIT COMMITTEE
                                                  REPORTING POLICY
------------------------------------------- ------------------------------
o These services are not to be              o A summary of all
  performed with the exception of the(*)      services and related
  services that may be permitted              fees reported at each
  if they would not be subject to audit       regularly scheduled
  procedures at the audit client (as          Audit Committee meeting
  defined in rule 2-01(f)(4)) level           will serve as continual
  the firm providing the service.             confirmation that has
  				              not provided any
                                              restricted services.
------------------------------------------- ------------------------------

--------------------------------------------------------------------------------
GENERAL AUDIT COMMITTEE APPROVAL POLICY:
o For all projects, the officers of the Funds and the Fund's auditors will each
  make an assessment to determine that any proposed projects will not impair
  independence.

o Potential services will be classified into the four non-restricted service
  categories and the "Approval of Audit, Audit-Related, Tax and Other
  Services" Policy above will be applied. Any services outside the specific
  pre-approved service subcategories set forth above must be specifically
  approved by the Audit Committee.

o At least quarterly, the Audit Committee shall review a report summarizing the
  services by service category, including fees, provided by the Audit firm as
  set forth in the above policy.

--------------------------------------------------------------------------------


    (2) Disclose the percentage of services described in each of paragraphs (b)
   through (d) of this Item that were approved by the audit committee pursuant
   to paragraph (c)(7)(i)(C) of Rule 2-01 of Regulation S-X.

N/A


(f) If greater than 50 percent, disclose the percentage of hours expended on the
principal accountants engagement to audit the registrant's financial statements
for the most recent fiscal year that were attributed to work performed by
persons other than the principal accountant's full-time, permanent employees.

N/A

(g) Disclose the aggregate non-audit fees billed by the registrants accountant
for services rendered to the registrant, and rendered to the registrants
investment adviser (not including any sub-adviser whose role is primarily
portfolio management and is subcontracted with or overseen by another investment
adviser), and any entity controlling, controlled by, or under common control
with the adviser that provides ongoing services to the registrant for each of
the last two fiscal years of the registrant.

N/A

(h) Disclose whether the registrants audit committee of the board of trustees
has considered whether the provision of non-audit services that were rendered to
the registrants investment adviser (not including any subadviser whose role is
primarily portfolio management and is subcontracted with or overseen by another
investment adviser), and any entity controlling, controlled by, or under common
control with the investment adviser that provides ongoing services to the
registrant that were not pre-approved pursuant to paragraph (c)(7)(ii) of
Rule 2-01 of Regulation S-X is compatible with maintaining the principal
accountant's independence.

The Funds audit committee of the Board of Trustees has considered whether
the provision of non-audit services that were rendered to the Affiliates
(as defined) that were not pre-approved pursuant to
paragraph (c)(7)(ii) of Rule 2-01 of Regulation S-X is compatible with
maintaining the principal accountant's independence.

ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS

(a) If the registrant is a listed issuer as defined in Rule 10A-3
under the Exchange Act (17 CFR 240.10A-3), state whether
or not the registrant has a separately-designated standing
 audit committee established in accordance with Section
3(a)(58)(A) of the Exchange Act (15 U.S.C. 78c(a)(58)(A)).
If the registrant has such a committee, however designated,
identify each committee member. If the entire board of directors
is acting as the registrant's audit committee as specified in
Section 3(a)(58)(B) of the Exchange Act (15 U.S.C. 78c(a)(58)(B)),
so state.

N/A

(b) If applicable, provide the disclosure required by Rule 10A-3(d)
under the Exchange Act (17 CFR 240.10A-3(d)) regarding an exemption
from the listing standards for audit committees.

N/A

ITEM 6. SCHEDULE OF INVESTMENTS.

File Schedule of Investments in securities of unaffiliated issuers
as of the close of the reporting period as set forth in 210.1212
of Regulation S-X [17 CFR 210.12-12], unless the schedule is
included as part of the report to shareholders filed under Item
1 of this Form.

Included in Item 1


ITEM 7. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR
CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

A closed-end management investment company that is filing an annual report on
this Form N-CSR must, unless it invests exclusively in non-voting securities,
describe the policies and procedures that it uses to determine how to vote
proxies relating to portfolio securities, including the procedures that the
company uses when a vote presents a conflict between the interests of its
shareholders, on the one hand, and those of the company's investment adviser;
principal underwriter; or any affiliated person (as defined in Section 2(a)(3)
of the Investment Company Act of 1940 (15 U.S.C. 80a-2(a)(3)) and the rules
thereunder) of the company, its investment adviser, or its principal
underwriter, on the other. Include any policies and procedures of the company's
investment adviser, or any other third party, that the company uses, or that are
used on the company's behalf, to determine how to vote proxies relating to
portfolio securities.

Not applicable to semi-annual reporting



ITEM 8. PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

(a) If the registrant is a closed-end management investment company that
is filing an annual report on this Form N-CSR,provide the following
information:
(1) State the name, title, and length of service of the person or persons
employed by or associated with the registrant or an investment adviser
of the registrant who are primarily responsible for the day-to-day management
of the registrant's portfolio ("Portfolio Manager"). Also state each Portfolio
Manager's business experience during the past 5 years.


Not applicable to semi-annual reporting


ITEM 9. PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT
INVESTMENT COMPANY AND AFFILIATED PURCHASERS.

(a) If the registrant is a closed-end management investment company,
in the following tabular format, provide the information specified in
paragraph (b) of this Item with respect to any purchase made by or on
behalf of the registrant or any affiliated purchaser, as defined in
Rule 10b-18(a)(3) under the Exchange Act (17 CFR 240.10b-18(a)(3)), of
shares or other units of any class of the registrant's equity securities
that is registered by the registrant pursuant to Section 12 of the
Exchange Act (15 U.S.C. 781).

Not applicable to semi-annual reporting


ITEM 10. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.

Describe any material changes to the procedures by which shareholders
may recommend nominees to the registrant's board of directors, where
those changes were implemented after the registrant last provided
disclosure in response to the requirements of Item 407(c)(2)(iv) of
Regulation S-R(17 CFR 229.407)(as required by Item 22(b)(15))
of Schedule 14A (17 CFR 240.14a-101), or this Item.


There have been no material changes to the procedures by which the
shareholders may recommend nominees to the registrant's board of
directors since the registrant last provided disclosure in response
to the requirements of Item 407(c)(2)(iv) of Regulation S-R of Schedule 14(A)
in its definitive proxy statement, or this item.


ITEM 11. CONTROLS AND PROCEDURES.

(a) Disclose the conclusions of the registrant's principal executive and
principal financials officers, or persons performing similar functions,
regarding the effectiveness of the registrant's disclosure
controls and procedures (as defined in Rule 30a-3(c) under the Act (17 CFR
270.30a-3(c))) as of a date within 90 days of the filing date of the report
that includes the disclosure required by this paragraph,
based on the evaluation of these controls and procedures required by Rule
30a-3(b) under the Act (17 CFR 270.30(a)-3(b) and Rules 13a-15(b) or 15d-15(b)
under the Exchange Act (17 CFR 240.13a-15(b) or 240.15d-15(b)).

The registrant's principal executive officer
and principal financial officer have
concluded that the registrant's disclosure
controls and procedures are effective based
on the evaluation of these controls and
procedures as of a date within 90 days of the
filing date of this report.


(b) Disclose any change in the registrant's internal control over financial
reporting (as defined in Rule 30a-3(d) under the Act (17CFR 270.30a-3(d)) that
occured during the second fiscal quarter of the period covered by this report
that has materially affected, or is reasonably likely to materially affect,
the registrant's internal control over financial reporting.

There were no significant changes in the
registrant's internal control over financial
reporting that occurred during the second
fiscal quarter of the period covered by this
report that have materially affected, or are
reasonably likely to materially affect, the
registrant's internal control over financial
reporting.

The registrant's principal executive officer and principal financial
officer, however, voluntarily are reporting the following information:

In August of 2006 the registrant's investment adviser
enhanced its internal procedures for reporting performance
information required to be included in prospectuses.
Those enhancements involved additional internal controls
over the appropriateness of performance data
generated for this purpose.  Such enhancements were made
following an internal review which identified
prospectuses relating to certain classes of shares of
a limited number of registrants where, inadvertently,
performance information not reflecting the deduction of
applicable sales charges was included. Those prospectuses
were revised, and the revised prospectuses were distributed to
shareholders.


ITEM 12. EXHIBITS.

(a) File the exhibits listed below as part of this Form. Letter or number the
exhibits in the sequence indicated.

(1) Any code of ethics, or amendment thereto, that is the subject of the
disclosure required by Item 2, to the extent that the registrant intends to
satisfy the Item 2 requirements through filing of an exhibit.



(2) A separate certification for each principal executive officer and principal
financial officer of the registrant as required by Rule 30a-2(a) under the Act
(17 CFR 270.30a-2(a)) , exactly as set forth below:

Filed herewith.





                                   SIGNATURES

                          [See General Instruction F]


Pursuant to the requirements of the Securities Exchange Act of 1934 and the
Investment Company Act of 1940, the registrant has duly caused this report to be
signed on its behalf by the undersigned, thereunto duly authorized.


(Registrant) Pioneer Municipal High Income Trust


By (Signature and Title)* /s/ Lisa M. Jones
Lisa M. Jones, President & Chief Executive Officer

Date December 29, 2014


Pursuant to the requirements of the Securities Exchange Act of 1934 and the
Investment Company Act of 1940, this report has been signed below by the
following persons on behalf of the registrant and in the capacities and on the
dates indicated.


By (Signature and Title)* /s/ Lisa M. Jones
Lisa M. Jones, President & Chief Executive Officer

Date December 29, 2014


By (Signature and Title)* /s/ Mark Bradley
Mark Bradley, Treasurer & Chief Accounting & Financial Officer

Date December 29, 2014

* Print the name and title of each signing officer under his or her signature.