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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, 2015 through October 31, 2015


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, 2015
--------------------------------------------------------------------------------

                        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                                                              9

Prices and Distributions                                                      10

Performance Update                                                            11

Schedule of Investments                                                       12

Financial Statements                                                          21

Financial Highlights                                                          24

Notes to Financial Statements                                                 26

Approval of Investment Advisory Agreement                                     35

Trustees, Officers and Service Providers                                      39


            Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 1


President's Letter

Dear Shareholder,

Through the first three quarters of 2015, global markets experienced pockets of
higher-than-average volatility due to significant cross-currents from different
geographic regions. All year, investors focused on the Federal Reserve System's
(the Fed's) deliberations over when to begin normalizing interest rates.
However, while there were signs of gradual economic improvement in the U.S.,
economies abroad increasingly diverged. In June, for example, investors grew
concerned about the debt crisis in Greece. That news, in turn, was followed by
evidence of an economic slowdown in China, which only served to exacerbate
existing worries about growth trends in the emerging markets, a segment of the
global economy already being negatively impacted by slumping commodity prices,
including the price of crude oil, which has been in near-steady decline for
almost a year. Through September 30, 2015, the pockets of heightened market
volatility alluded to above had resulted in the Standard & Poor's 500 Index
turning in a negative (-5.27%) return over the first nine months of the year.
However, the S&P 500 recovered nicely in October, returning 8.43% for the month,
which boosted the index's year-to-date return into positive territory, at 2.71%.

Despite the headwinds still vexing the global economy, our longer-term view of
the U.S. economy has remained positive. Economic conditions in the U.S. have
generally been constructive, based largely on improvements in employment
statistics and an uptick in the housing sector, which has aided the consumer
side of the economy, where household spending has been rising modestly. U.S.
consumers also stand to benefit, potentially, from lower energy prices as the
winter weather approaches. We continue to believe the U.S. economy remains on
a slow, steady growth trend, and that it is unlikely to be disrupted by a slow
pace of interest-rate normalization by the Fed.

Pioneer Investments believes that investors in today's environment can
potentially benefit from the consistent and disciplined investment approach we
have used since our founding in 1928. We focus on identifying value across
global markets using proprietary research, careful risk management, and a
long-term perspective. Our ongoing goal is to produce compelling returns
consistent with the stated objectives of our investment products, and with our
shareowners' expectations. We believe our shareowners can benefit from the
experience and tenure of our investment teams as well as the insights generated
from our extensive research process.

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


As always, and particularly during times of market uncertainty, we encourage you
to work with your financial advisor to develop an overall investment plan that
addresses both your short- and long-term goals, and to implement such a plan in
a disciplined manner.

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.
November 2, 2015

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 | 10/31/15 3


Portfolio Management Discussion | 10/31/15

Municipal bonds, both high-yield and investment-grade, generated modest results
during the six-month period ended October 31, 2015. 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.
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, 2015?

A    Pioneer Municipal High Income Trust returned 3.22% at net asset value and
     -7.91% at market price during the six-month period ended October 31, 2015.
     During the same six-month period, the Trust's benchmarks, the Barclays High
     Yield Municipal Bond Index and the Barclays Municipal Bond Index, returned
     0.55% and 1.68% 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 -0.64%.

     The shares of the Trust were selling at a 1.1% discount to net asset value
     at the end of the period on October 31, 2015.

     On October 31, 2015, the standardized 30-day SEC yield of the Trust's
     shares was 3.84%*.

Q    How would you describe the investment environment in the municipal bond
     market during the six-month period ended October 31, 2015?

A    The primary municipal market indices showed positive results over the six
     months, with investment-grade bonds performing somewhat better than
     lower-rated, higher-yielding bonds, even after a rise in longer-term
     interest rates late in the period. The key driver of the market during the
     six-month

*    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 | 10/31/15


     period was the persistence of demand for municipal bonds from both
     traditional, tax-conscious investors as well as from non-traditional
     investors drawn in by the attractive relative values of municipal bonds.

     The performance of lower-rated municipals trailed the return of
     investment-grade municipals during the period, primarily due to the
     negative influence that bonds issued by the Commonwealth of Puerto Rico had
     on the high-yield asset class. Municipals issued by Puerto Rican
     municipalities and institutions, which accounted for as much as 26% of the
     high-yield municipal market during the period, plummeted in value after
     Puerto Rico's governor announced in June that, within weeks, all of the
     Commonwealth's bonds would need to be restructured. While Puerto Rican debt
     did recover somewhat later in the period, the negative effects of the
     restructuring situation lingered and caused the high-yield municipal market
     to underperform the investment-grade segment. Fortunately, the Trust's
     portfolio had very low exposure to Puerto Rican bonds during the period
     (roughly 1%), and so the Trust managed to avoid most of the negative
     consequences the underperformance of Puerto Rican debt had on the overall
     market.

Q    How did you manage the Trust's portfolio during the six-month period ended
     October 31, 2015, and which of your investment decisions had the biggest
     effects on the Trust's performance?

A    During the six-month period, we kept the Trust's portfolio well
     diversified**, emphasizing investments in the hospital/health care,
     transportation, and education sectors as well as tobacco settlement bonds.
     Consistent with our long-term investment approach, we continued to
     emphasize holding bonds in the portfolio that are backed by specific
     projects (project revenue bonds). We prefer project revenue bonds to
     general obligation (G.O.) bonds, which are issued by state and local
     governments.

     We believe the consistent, predictable revenue streams behind project
     revenue bonds are more reliable than the revenue sources backing G.O.
     bonds, which can at times be less predictable and reliable.

     At the end of the period, on October 31, 2015, only 9.9% of the Trust's
     total investment portfolio was allocated to general obligation bonds.

     With regard to benchmark-relative performance, overall security selection
     results, the Trust's significant underweight to Puerto Rico-issued bonds,
     and a relatively large portfolio exposure to tobacco settlement bonds all
     had positive effects on the Trust's relative returns.

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

            Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 5


     Some individual securities in the Trust's portfolio that had positive
     effects on the Trust's benchmark-relative performance during the period
     included: a general obligation bond issued by the State of Washington; an
     education bond backed by revenues at Emory University in Atlanta; and a
     hospital/health care bond backed by Temple Hospital in Philadelphia. On the
     negative side, the Trust saw disappointing performance from some portfolio
     holdings, including: an education bond backed by a college in Phillippi,
     West Virginia; a hospital/health care bond backed by Langhorne Manor, a
     continuing care retirement community in Pennsylvania; and a security backed
     by a correctional facility in Central Falls, Rhode Island.

Q    Did you use any derivatives in managing the Trust's portfolio during the
     six-month period ended October 31, 2015? If so, did the use of derivatives
     affect the Trust's performance?

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

Q    What were the principal factors affecting the Trust's yield, or
     distributions to shareholders, during the six-month period ended October
     31, 2015?

A    The Trust's dividend*** remained stable during the six-month period.
     However, we continued to see bonds with higher book yields - which we had
     purchased opportunistically several years ago when the municipal market was
     struggling and yields were elevated - called away by their issuers due to
     the persistent low-interest-rate environment. Those bonds, in turn, were
     replaced in the Trust's portfolio with lower-yielding market securities. We
     expect this scenario to prevail for the foreseeable future, and that could
     have a negative effect on the Trust's distributions going forward.

     It also should be noted that, primarily due to the low-interest-rate
     conditions detailed above, the Trust reduced its dividend earlier in the
     calendar year. The reduction of the dividend likely had a carryover effect
     on the Trust's market price during the six-month period ended October 31,
     2015.

Q    How did the level of leverage in the Trust change during the six-month
     period ended October 31, 2015?

A    At the end of the six-month period on October 31, 2015, 25.1% of the
     Trust's total managed assets were financed by leverage (or borrowed funds),
     compared with 25.0% of the Trust's total managed assets financed by
     leverage at the start of the period on May 1, 2015. The percentage increase
     was due to a decrease in the value of securities in which the Trust had
     invested.

***  Dividends are not guaranteed.

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


Q    What is your outlook?

A    With improving employment numbers and low inflation, we believe there will
     be continued, modest growth in the domestic economy. Our outlook is also
     positive with regard to potential opportunities in the municipal bond
     market, especially in the high-yield segment. Municipal securities remain
     attractively valued compared with prices of debt instruments of comparable
     quality and maturity that are available in the taxable market, and we think
     it is realistic to expect that demand for municipals will persist, while
     the supply of new issues remains limited.

Please refer to the Schedule of Investments on pages 12-20 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.

            Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 7


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, which is
likely to result in a decrease in the market value of the Trust's shares.

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.

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


Portfolio Summary | 10/31/15

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

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



                                                                        
Insured                                                                    14.5%
Revenue Bonds:
Other Revenue                                                              25.7%
Health Revenue                                                             12.4%
Facilities Revenue                                                         11.3%
Development Revenue                                                        10.3%
Education Revenue                                                           9.4%
Tobacco Revenue                                                             8.8%
Transportation Revenue                                                      2.9%
Airport Revenue                                                             2.1%
Water Revenue                                                               1.4%
Pollution Control Revenue                                                   1.2%


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



                                                                                         
  1. Metropolitan Pier & Exposition Authority, McCormick Place, Series B, 6/15/22           4.38%
-------------------------------------------------------------------------------------------------
  2. State of Washington, Motor Vehicle Sales Tax, Series C, 6/1/22                         3.30
-------------------------------------------------------------------------------------------------
  3. Lehman Municipal Trust Receipts, RIB, 14.101%, 8/21/35                                 2.93
-------------------------------------------------------------------------------------------------
  4. North Texas Tollway Authority, Series F, 5.75%, 1/1/33                                 2.92
-------------------------------------------------------------------------------------------------
  5. Lehman Municipal Trust Receipts, RIB, 13.235%, 9/20/28 (144A)                          2.62
-------------------------------------------------------------------------------------------------
  6. Massachusetts Development Finance Agency, WGBH Foundation, Series A, 5.75%, 1/1/42     2.28
-------------------------------------------------------------------------------------------------
  7. New York State Dormitory Authority, Series C, 5.0%, 3/15/39                            2.23
-------------------------------------------------------------------------------------------------
  8. New York State Dormitory Authority, RIB, 16.07%, 5/29/14 (144A)                        2.06
-------------------------------------------------------------------------------------------------
  9. Public Finance Authority, Glenridge Palmer Ranch, Series A, 8.25%, 6/1/46              1.63
-------------------------------------------------------------------------------------------------
 10. District of Columbia Tobacco Settlement Financing Corp., Asset-Backed, 6.5%, 5/15/33   1.63
-------------------------------------------------------------------------------------------------


*    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.

            Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 9


Prices and Distributions | 10/31/15

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



--------------------------------------------------------------------------------
                                         10/31/15                     4/30/15
--------------------------------------------------------------------------------
                                                                 
        Market Value                      $13.14                       $14.75
--------------------------------------------------------------------------------
        (Discount)/Premium                (1.1)%                        10.8%
--------------------------------------------------------------------------------


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



--------------------------------------------------------------------------------
                                         10/31/15                     4/30/15
--------------------------------------------------------------------------------
                                                                 
        Net Asset Value                   $13.29                       $13.31
--------------------------------------------------------------------------------


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



--------------------------------------------------------------------------------
                                              Short-Term         Long-Term
                             Dividends       Capital Gains      Capital Gains
--------------------------------------------------------------------------------
                                                           
     5/1/15 - 10/31/15         $0.42             $ --               $ --
--------------------------------------------------------------------------------


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

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


Performance Update | 10/31/15

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, 2015)
--------------------------------------------------------------------------------
                                                    Barclays
                                       Barclays     High Yield
                 Net                   Municipal    Municipal
                 Asset                 Bond         Bond
                 Value      Market     Index        Index
Period           (NAV)      Price      (NAV)        (NAV)
--------------------------------------------------------------------------------
                                        
10 Years         6.38%       6.58%     4.74%        4.97%
5 Years          6.64        5.19      4.28         6.08
1 Year           5.59       -7.64      2.87         2.85
--------------------------------------------------------------------------------


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

Value of $10,000 Investment



                           Pioneer Municipal      Barclays High Yield     Barclays Municipal
                           High Income Trust      Municipal Bond Index    Bond Index
                                                                 
10/05                      $10,000                $10,000                 $10,000
10/06                      $10,648                $11,187                 $10,575
10/07                      $11,357                $11,440                 $10,882
10/08                      $ 7,872                $ 9,275                 $10,523
10/09                      $11,895                $10,623                 $11,954
10/10                      $14,687                $12,096                 $12,884
10/11                      $15,134                $12,502                 $13,371
10/12                      $18,346                $14,619                 $14,578
10/13                      $17,721                $14,251                 $14,328
10/14                      $20,483                $15,796                 $15,448
10/15                      $18,918                $16,246                 $15,891


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 1,300
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.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 11


Schedule of Investments | 10/31/15 (unaudited)



------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                           Value
------------------------------------------------------------------------------------------------
                                                                            
                    TAX EXEMPT OBLIGATIONS -- 125.3%
                    of Net Assets (a)
                    Alabama -- 1.5%
     4,500,000      Huntsville-Redstone Village Special Care Facilities
                    Financing Authority, Redstone Village Project,
                    5.5%, 1/1/43                                                  $    4,509,225
------------------------------------------------------------------------------------------------
                    Arizona -- 0.0%+
        24,000      County of Pima, AZ, Industrial Development Authority,
                    Arizona Charter Schools Project, Series C, 6.75%, 7/1/31      $       24,043
------------------------------------------------------------------------------------------------
                    California -- 10.5%
    10,000,000(b)   California County Tobacco Securitization Agency,
                    Capital Appreciation, Stanislaus County, Subordinated,
                    Series A, 6/1/46                                              $    1,122,400
     1,450,000      California Enterprise Development Authority,
                    Sunpower Corp., 8.5%, 4/1/31                                       1,653,493
      750,000       California Municipal Finance Authority, Santa Rosa
                    Academy Project, Series A, 5.75%, 7/1/30                             794,587
     5,000,000      California Pollution Control Financing Authority,
                    5.0%, 7/1/37 (144A)                                                5,140,000
     1,740,000      California School Finance Authority, Classical Academies
                    Project, Series A, 7.375%, 10/1/43                                 2,054,366
     1,400,000      California Statewide Communities Development
                    Authority, Lancer Plaza Project, 5.625%, 11/1/33                   1,419,334
       568,006(c)   California Statewide Communities Development
                    Authority, Microgy Holdings Project, 9.0%, 12/1/38                         6
    25,000,000(b)   Inland Empire Tobacco Securitization Authority, Capital
                    Appreciation, Asset-Backed, Series C-2, 6/1/47                     2,023,500
     7,885,000(d)   Lehman Municipal Trust Receipts, RIB, 13.235%,
                    9/20/28 (144A)                                                     9,949,056
     2,000,000(e)   Los Angeles Community College District, Series G,
                    4.0%, 8/1/39                                                       2,071,700
     1,000,000      River Islands Public Financing Authority, Community
                    Facilities, 5.5%, 9/1/45                                           1,035,290
     2,000,000      Tobacco Securitization Authority of Northern California,
                    Asset-Backed, Series A-1, 5.375%, 6/1/38                           1,769,800
     3,000,000      Tobacco Securitization Authority of Southern California,
                    Series A-1, 5.0%, 6/1/37                                           2,696,280
                                                                                  --------------
                                                                                  $   31,729,812
------------------------------------------------------------------------------------------------
                    Colorado -- 1.5%
     1,500,000      Colorado Educational & Cultural Facilities Authority,
                    Rocky Mountain Classical Academy Project, 8.0%, 9/1/43        $    1,583,535
     2,000,000      Colorado Health Facilities Authority, Valley View
                    Association Project, 5.25%, 5/15/42                                2,091,020
     1,000,000      Kremmling Memorial Hospital District, Certificate of
                    Participation, 7.125%, 12/1/45                                       999,970
                                                                                  --------------
                                                                                  $    4,674,525
------------------------------------------------------------------------------------------------


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

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




------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                           Value
------------------------------------------------------------------------------------------------
                                                                            
                    Connecticut -- 7.4%
    10,335,000(d)   Lehman Municipal Trust Receipts, RIB, 14.101%, 8/21/35 $          11,118,806
     5,000,000      Mohegan Tribe of Indians Gaming Authority, 6.25%, 1/1/31           4,988,800
     5,000,000(e)   State of Connecticut, Series E, 4.0%, 9/1/30                       5,301,650
     1,000,000      Town of Hamden, CT, Whitney Center Project, Series A,
                    7.75%, 1/1/43                                                      1,042,660
                                                                                  --------------
                                                                                  $   22,451,916
------------------------------------------------------------------------------------------------
                    District of Columbia -- 4.0%
     5,000,000      District of Columbia Tobacco Settlement Financing Corp.,
                    Asset-Backed, 6.5%, 5/15/33                                   $    6,165,300
     6,000,000      District of Columbia Tobacco Settlement Financing Corp.,
                    Asset-Backed, 6.75%, 5/15/40                                       6,000,300
                                                                                  --------------
                                                                                  $   12,165,600
------------------------------------------------------------------------------------------------
                    Florida -- 4.8%
     1,500,000      Alachua County Health Facilities Authority, Terraces
                    Bonita Springs Project, Series A, 8.125%, 11/15/41            $    1,772,205
     1,500,000      Alachua County Health Facilities Authority, Terraces
                    Bonita Springs Project, Series A, 8.125%, 11/15/46                 1,768,560
       500,000      Capital Trust Agency, Inc., Million Air One LLC,
                    7.75%, 1/1/41                                                        474,330
     2,260,000(c)   County of Liberty, FL, Twin Oaks Project, 8.25%, 7/1/28              337,056
     2,500,000      County of Miami-Dade, FL, Aviation Revenue, Series B,
                    5.5%, 10/1/41                                                      2,812,650
     5,000,000      Florida's Turnpike Enterprise, Department of Transportation,
                    Series A, 4.0%, 7/1/34                                             5,219,600
     1,000,000(f)   Hillsborough County Industrial Development Authority,
                    Various Health Facilities, 8.0%, 8/15/32                           1,265,570
     2,250,000(d)   St. Johns County Industrial Development Authority,
                    Glenmoor Project, Series A, 1.344%, 1/1/49                           779,198
       832,581(c)   St. Johns County Industrial Development Authority,
                    Glenmoor Project, Series B, 2.5%, 1/1/49                                   8
                                                                                  --------------
                                                                                  $   14,429,177
------------------------------------------------------------------------------------------------
                    Georgia -- 2.5%
     2,500,000      Clayton County Development Authority, Delta Air Lines,
                    Series A, 8.75%, 6/1/29                                       $    3,058,650
     4,000,000      Private Colleges & Universities Authority, Emory University,
                    Series A, 5.0%, 10/1/43                                            4,545,000
                                                                                  --------------
                                                                                  $    7,603,650
------------------------------------------------------------------------------------------------
                    Idaho -- 1.6%
     5,000,000      Power County Industrial Development Corp., FMC Corp.
                    Project, 6.45%, 8/1/32                                        $    5,009,550
------------------------------------------------------------------------------------------------


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

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 13


Schedule of Investments | 10/31/15 (unaudited) (continued)



------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                           Value
------------------------------------------------------------------------------------------------
                                                                            
                    Illinois -- 14.5%
     240,000        Illinois Finance Authority, Clare Oaks Project, Series A-3,
                    7.0%, 11/15/17                                                $      240,084
   2,087,000(d)     Illinois Finance Authority, Clare Oaks Project, Series B,
                    4.0%, 11/15/52                                                     1,333,948
   1,305,000(b)     Illinois Finance Authority, Clare Oaks Project, Series C-1,
                    11/15/52                                                              46,967
     261,000(b)     Illinois Finance Authority, Clare Oaks Project, Series C-2,
                    11/15/52                                                              71,250
     261,000(b)     Illinois Finance Authority, Clare Oaks Project, Series C-3,
                    11/15/52                                                              44,858
   2,000,000        Illinois Finance Authority, Greenfields of Geneva Project,
                    Series A, 8.125%, 2/15/40                                          2,114,360
   2,500,000        Illinois Finance Authority, Greenfields of Geneva Project,
                    Series A, 8.25%, 2/15/46                                           2,648,750
   2,000,000        Illinois Finance Authority, Northwestern Memorial Hospital,
                    Series A, 6.0%, 8/15/39                                            2,303,300
   2,500,000        Illinois Finance Authority, Roosevelt University Project,
                    6.5%, 4/1/39                                                       2,710,400
   3,865,000        Illinois Finance Authority, Swedish Covenant, Series A,
                    6.0%, 8/15/38                                                      4,279,174
   1,700,000        Illinois Finance Authority, The Admiral at the Lake Project,
                    Series A, 7.625%, 5/15/25                                          1,924,927
    600,000         Illinois Finance Authority, The Admiral at the Lake Project,
                    Series A, 7.75%, 5/15/30                                             682,440
   2,000,000        Illinois Finance Authority, The Admiral at the Lake Project,
                    Series A, 8.0%, 5/15/40                                            2,286,360
   3,200,000        Illinois Finance Authority, The Admiral at the Lake Project,
                    Series A, 8.0%, 5/15/46                                            3,654,496
   1,485,000(b)(g)  Metropolitan Pier & Exposition Authority, McCormick Place,
                    Series B, 6/15/22                                                  1,680,916
  15,395,000(b)     Metropolitan Pier & Exposition Authority, McCormick Place,
                    Series B, 6/15/22                                                 16,616,439
   1,140,000        Southwestern Illinois Development Authority, Village of
                    Sauget Project, 5.625%, 11/1/26                                    1,051,582
                                                                                  --------------
                                                                                  $   43,690,251
------------------------------------------------------------------------------------------------
                    Indiana -- 1.8%
    250,000         City of Carmel, IN, Barrington Carmel Project, Series A,
                    7.0%, 11/15/32                                                $      279,365
    750,000         City of Carmel, IN, Barrington Carmel Project, Series A,
                    7.125%, 11/15/42                                                     838,882
    500,000         City of Carmel, IN, Barrington Carmel Project, Series A,
                    7.125%, 11/15/47                                                     557,690
   3,570,000        Vigo County Hospital Authority, Union Hospital, Inc.,
                    5.8%, 9/1/47 (144A)                                                3,691,880
                                                                                  --------------
                                                                                  $    5,367,817
------------------------------------------------------------------------------------------------


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

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




------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                           Value
------------------------------------------------------------------------------------------------
                                                                            
                    Kentucky -- 1.9%
     5,000,000      Kentucky Economic Development Finance Authority,
                    Owensboro Medical Health System, Series A,
                    6.375%, 6/1/40                                                $    5,720,150
------------------------------------------------------------------------------------------------
                    Louisiana -- 3.1%
     2,260,000      Jefferson Parish Hospital Service District No. 2, East
                    Jefferson General Hospital, 6.375%, 7/1/41                    $    2,554,908
     1,500,000      Louisiana Local Government Environmental Facilities &
                    Community Development Authority, Westlake Chemical
                    Corp. Project, 6.75%, 11/1/32                                      1,626,240
     1,380,000(f)   Louisiana Public Facilities Authority, Ochsner Clinic
                    Foundation Project, Series A, 5.5%, 5/15/47                        1,484,866
     3,620,000      Louisiana Public Facilities Authority, Ochsner Clinic
                    Foundation Project, Series A, 5.5%, 5/15/47                        3,791,805
                                                                                  --------------
                                                                                  $    9,457,819
------------------------------------------------------------------------------------------------
                    Maine -- 2.3%
     1,500,000      Maine Health & Higher Educational Facilities Authority,
                    Maine General Medical Center, 7.5%, 7/1/32                    $    1,793,235
     4,480,000      Maine Turnpike Authority, Series A, 5.0%, 7/1/42                   5,051,424
                                                                                  --------------
                                                                                  $    6,844,659
------------------------------------------------------------------------------------------------
                    Maryland -- 0.5%
     1,490,000      Maryland Health & Higher Educational Facilities Authority,
                    City Neighbors, Series A, 6.75%, 7/1/44                       $    1,611,405
------------------------------------------------------------------------------------------------
                    Massachusetts -- 3.3%
       987,910      Massachusetts Development Finance Agency, Linden
                    Ponds, Inc., Series A-1, 5.5%, 11/15/46                       $      841,729
     7,100,000      Massachusetts Development Finance Agency, WGBH
                    Foundation, Series A, 5.75%, 1/1/42                                8,644,250
       525,000      Massachusetts Educational Financing Authority, Series I,
                    6.0%, 1/1/28                                                         557,282
     4,500,000(c)   Massachusetts Health & Educational Facilities Authority,
                    Quincy Medical Center, Series A, 6.5%, 1/15/38                        11,025
                                                                                  --------------
                                                                                  $   10,054,286
------------------------------------------------------------------------------------------------
                    Michigan -- 3.5%
       895,000(c)   Doctor Charles Drew Academy, Certificate of Participation,
                    5.7%, 11/1/36                                                 $      178,875
     2,000,000      Kent Hospital Finance Authority, Metropolitan Hospital
                    Project, Series A, 6.25%, 7/1/40                                   2,001,280
     2,640,000      Michigan State University, Series A, 5.0%, 8/15/41                 2,963,373
     6,100,000      Michigan Tobacco Settlement Finance Authority, Series A,
                    6.0%, 6/1/48                                                       5,412,591
                                                                                  --------------
                                                                                  $   10,556,119
------------------------------------------------------------------------------------------------


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

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


Schedule of Investments | 10/31/15 (unaudited) (continued)



------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                           Value
------------------------------------------------------------------------------------------------
                                                                            
                    Minnesota -- 0.7%
     2,000,000      Bloomington Port Authority, Radisson Blu Mall of America,
                    9.0%, 12/1/35                                                 $    2,288,560
------------------------------------------------------------------------------------------------
                    Montana -- 0.1%
     1,600,000(c)   Two Rivers Authority, Inc., 7.375%, 11/1/27                   $      230,784
------------------------------------------------------------------------------------------------
                    New Jersey -- 2.0%
     3,000,000      New Jersey Economic Development Authority, Continental
                    Airlines, 5.25%, 9/15/29                                      $    3,261,060
     2,500,000      New Jersey Economic Development Authority, Continental
                    Airlines, 5.75%, 9/15/27                                           2,698,225
                                                                                  --------------
                                                                                  $    5,959,285
------------------------------------------------------------------------------------------------
                    New Mexico -- 1.5%
     1,500,000      County of Otero, NM, Otero County Jail Project, 6.0%,
                    4/1/23                                                        $    1,499,115
     2,960,000      County of Otero, NM, Otero County Jail Project, 6.0%,
                    4/1/28                                                             2,942,684
                                                                                  --------------
                                                                                  $    4,441,799
------------------------------------------------------------------------------------------------
                    New York -- 10.1%
     2,000,000      Chautauqua County Capital Resource Corp., Women's
                    Christian Association Project, Series A, 8.0%, 11/15/30       $    2,058,860
     2,000,000      Hempstead Local Development Corp., Molloy College
                    Project, 5.75%, 7/1/39                                             2,229,100
     2,000,000      New York City Industrial Development Agency, British Airways
                    Plc Project, 5.25%, 12/1/32                                        2,005,340
     2,000,000      New York City Industrial Development Agency, British Airways
                    Plc Project, 7.625%, 12/1/32                                       2,027,340
     1,000,000      New York State Dormitory Authority, Orange Medical Center,
                    6.125%, 12/1/29                                                    1,092,200
     7,040,000(d)   New York State Dormitory Authority, RIB, 16.07%,
                    5/29/14 (144A)                                                     7,804,473
     7,500,000      New York State Dormitory Authority, Series C, 5.0%,
                    3/15/39                                                            8,467,050
     1,500,000      New York State Dormitory Authority, Trustees of Columbia
                    University, 5.0%, 10/1/45                                          1,985,910
     2,538,540      Westchester County Healthcare Corp., Series A, 5.0%,
                    11/1/44                                                            2,790,135
                                                                                  --------------
                                                                                  $   30,460,408
------------------------------------------------------------------------------------------------
                    North Dakota -- 1.0%
     2,525,000(f)   County of Burleigh, ND, St. Alexius Medical Center,
                    5.0%, 7/1/38                                                  $    3,044,771
------------------------------------------------------------------------------------------------
                    Ohio -- 4.4%
     2,500,000      Buckeye Tobacco Settlement Financing Authority,
                    Asset-Backed, Series A-2, 5.875%, 6/1/47                      $    2,146,850
     1,700,000      Buckeye Tobacco Settlement Financing Authority,
                    Asset-Backed, Series A-2, 6.0%, 6/1/42                             1,479,510


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

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




------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                           Value
------------------------------------------------------------------------------------------------
                                                                            
                    Ohio -- (continued)
     5,000,000      Buckeye Tobacco Settlement Financing Authority,
                    Asset-Backed, Series A-2, 6.5%, 6/1/47                        $    4,638,450
     2,000,000(d)   Ohio Air Quality Development Authority, FirstEnergy
                    Generation Corp. Project, 3.1%, 3/1/23                             2,006,880
     2,500,000(e)   State of Ohio, Common Schools, Series B, 5.0%, 6/15/29             2,938,025
                                                                                  --------------
                                                                                  $   13,209,715
------------------------------------------------------------------------------------------------
                    Oregon -- 1.9%
     5,190,000      Oregon Health & Science University, Series E, 5.0%,
                    7/1/32                                                        $    5,836,363
------------------------------------------------------------------------------------------------
                    Pennsylvania -- 6.2%
     1,550,000      Allegheny County Hospital Development Authority, South
                    Hills Health, Series A, 5.125%, 5/1/25                        $    1,559,812
     1,280,000(c)   Langhorne Manor Borough Higher Education Authority,
                    Lower Bucks Hospital, 7.35%, 7/1/22                                  243,059
     5,000,000      Pennsylvania Economic Development Financing Authority,
                    USG Corp. Project, 6.0%, 6/1/31                                    4,999,850
       500,000      Philadelphia Authority for Industrial Development, Greater
                    Philadelphia Health Action, Inc., Project, Series A,
                    6.625%, 6/1/50                                                       496,935
     2,000,000      Philadelphia Authority for Industrial Development, Nueva
                    Esperanze, Inc., 8.2%, 12/1/43                                     2,205,580
     1,000,000      Philadelphia Authority for Industrial Development,
                    Performing Arts Charter School Project, 6.5%,
                    6/15/33 (144A)                                                     1,046,490
     2,000,000      Philadelphia Authority for Industrial Development,
                    Performing Arts Charter School Project, 6.75%,
                    6/15/43 (144A)                                                     2,101,540
     5,900,000      Philadelphia Hospitals & Higher Education Facilities
                    Authority, Temple University Health System, Series A, 5.0%,
                    7/1/34                                                             5,984,488
                                                                                  --------------
                                                                                  $   18,637,754
------------------------------------------------------------------------------------------------
                    Puerto Rico -- 1.0%
     4,255,000(e)   Commonwealth of Puerto Rico, Series A, 8.0%, 7/1/35           $    3,106,108
------------------------------------------------------------------------------------------------
                    Rhode Island -- 1.1%
     5,900,000(c)   Central Falls Detention Facility Corp., 7.25%, 7/15/35        $    1,466,858
     1,500,000      Rhode Island Health & Educational Building Corp.,
                    Tockwatten Home Issue, 8.375%, 1/1/46                              1,773,630
                                                                                  --------------
                                                                                  $    3,240,488
------------------------------------------------------------------------------------------------
                    Tennessee -- 1.6%
     4,600,000      Sullivan County Health, Educational & Housing Facilities
                    Board, Wellmont Health System Project, Series C, 5.25%,
                    9/1/36                                                        $    4,735,654
------------------------------------------------------------------------------------------------


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

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 17


Schedule of Investments | 10/31/15 (unaudited) (continued)



------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                           Value
------------------------------------------------------------------------------------------------
                                                                            
                    Texas -- 15.3%
   1,000,000        Arlington Higher Education Finance Corp., Universal
                    Academy, Series A, 7.0%, 3/1/34                               $    1,056,680
   2,500,000        Central Texas Regional Mobility Authority, Sub Lien,
                    6.75%, 1/1/41                                                      2,984,025
   2,490,000(e)     County of Harris, TX, Series A, 5.0%, 10/1/26                      3,057,819
   5,000,000(e)     Goose Creek Consolidated Independent School District,
                    Series C, 4.0%, 2/15/26                                            5,586,700
    725,078(c)      Gulf Coast Industrial Development Authority, Microgy
                    Holdings Project, 7.0%, 12/1/36                                            7
   5,340,000        Lubbock Health Facilities Development Corp., Carillon
                    Project, Series A, 6.625%, 7/1/36                                  5,448,776
   3,785,000        North Texas Tollway Authority, Series A, 5.0%, 1/1/35              4,220,578
  10,000,000(f)     North Texas Tollway Authority, Series F, 5.75%, 1/1/33            11,067,000
   1,500,000        Red River Health Facilities Development Corp., MRC
                    Crestview, Series A, 8.0%, 11/15/41                                1,746,555
   3,960,000        Sanger Industrial Development Corp., Texas Pellets Project,
                    Series B, 8.0%, 7/1/38                                             4,253,357
   1,000,000        Tarrant County Cultural Education Facilities Finance
                    Corp., Mirador Project, Series A, 8.125%, 11/15/39                   850,000
   1,000,000        Tarrant County Cultural Education Facilities Finance
                    Corp., Mirador Project, Series A, 8.25%, 11/15/44                    850,010
   2,000,000        Tarrant County Cultural Education Facilities Finance
                    Corp., MRC Crestview Project, 8.0%, 11/15/34                       2,297,020
   2,500,000        Travis County Health Facilities Development Corp.,
                    Longhorn Village Project, 7.125%, 1/1/46                           2,785,450
                                                                                  --------------
                                                                                  $   46,203,977
------------------------------------------------------------------------------------------------
                    Virginia -- 1.4%
   4,000,000        Upper Occoquan Sewage Authority, 4.0%, 7/1/41                 $    4,172,720
------------------------------------------------------------------------------------------------
                    Washington -- 8.7%
  14,315,000(b)(e)  State of Washington, Motor Vehicle Sales Tax,
                    Series C, 6/1/22                                              $   12,507,731
   2,500,000        University of Washington, Series B, 5.0%, 6/1/29                   2,996,750
   3,795,000(f)     Washington State Health Care Facilities Authority, Fred
                    Hutchinson Cancer Research Center, Series A,
                    6.0%, 1/1/33                                                       4,467,892
   1,150,000        Washington State Housing Finance Commission, Mirabella
                    Project, Series A, 6.75%, 10/1/47                                  1,244,829
   5,000,000        Washington State Housing Finance Commission, Skyline
                    at First Hill Project, Series A, 5.625%, 1/1/27                    5,020,050
                                                                                  --------------
                                                                                  $   26,237,252
------------------------------------------------------------------------------------------------


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

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




------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                           Value
------------------------------------------------------------------------------------------------
                                                                            
                    West Virginia -- 0.6%
     2,000,000(c)   City of Philippi, WV, Alderson-Broaddus College, Inc.,
                    Series A, 7.75%, 10/1/44                                      $    1,199,960
       725,000      West Virginia Hospital Finance Authority, Highland
                    Hospital Group, 9.125%, 10/1/41                                      780,622
                                                                                  --------------
                                                                                  $    1,980,582
------------------------------------------------------------------------------------------------
                    Wisconsin -- 3.0%
     5,000,000      Public Finance Authority, Glenridge Palmer Ranch,
                    Series A, 8.25%, 6/1/46                                       $    6,193,150
       750,000      Public Finance Authority, Roseman University Health
                    Sciences Project, 5.875%, 4/1/45                                     769,313
     1,500,000      Public Finance Authority, SearStone CCRC Project,
                    Series A, 8.625%, 6/1/47                                           1,783,305
       230,000      Public Finance Authority, SearStone CCRC Project,
                    Series B, 8.375%, 6/1/20                                             230,761
                                                                                  --------------
                                                                                  $    8,976,529
------------------------------------------------------------------------------------------------
                    TOTAL TAX EXEMPT OBLIGATIONS
                    (Cost $353,665,851)                                           $  378,662,753
------------------------------------------------------------------------------------------------
                    MUNICIPAL COLLATERALIZED DEBT
                    OBLIGATION -- 0.2% of Net Assets
    10,000,000(d)   Non-Profit Preferred Funding Trust I, Series E, 0.0%,
                    9/15/37 (144A)                                                $      632,800
------------------------------------------------------------------------------------------------
                    TOTAL MUNICIPAL COLLATERALIZED DEBT OBLIGATION
                    (Cost $10,000,000)                                            $      632,800
------------------------------------------------------------------------------------------------
                    TOTAL INVESTMENTS IN SECURITIES -- 125.5%
                    (Cost -- $363,665,851) (h)                                    $  379,295,553
------------------------------------------------------------------------------------------------
                    OTHER ASSETS AND LIABILITIES -- 7.9%                          $   23,830,277
------------------------------------------------------------------------------------------------
                    PREFERRED SHARES AT REDEMPTION VALUE,
                    INCLUDING DIVIDENDS PAYABLE -- (33.4)%                        $ (101,001,423)
------------------------------------------------------------------------------------------------
                    NET ASSETS APPLICABLE TO
                    COMMON SHAREOWNERS -- 100.0%                                  $  302,124,407
================================================================================================


+         Amount rounds to less than 0.1%.

(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, 2015, the value of these securities amounted to
          $30,366,240, or 10.1% 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, 2015.

(a)       Consists of Revenue Bonds unless otherwise indicated.

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

(c)       Security is in default.

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

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 19


Schedule of Investments | 10/31/15 (unaudited) (continued)

(d)       The interest rate is subject to change periodically. The interest rate
          shown is the rate at October 31, 2015.

(e)       Represents a General Obligation Bond.

(f)       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.

(g)       Escrow to maturity.

(h)       At October 31, 2015, the net unrealized appreciation on investments
          based on cost for federal tax purposes of $358,178,311 was as follows:



                                                                             
          Aggregate gross unrealized appreciation for all investments in which
            there is an excess of value over tax cost                           $ 40,303,532

          Aggregate gross unrealized depreciation for all investments in which
            there is an excess of tax cost over value                            (19,186,290)
                                                                                ------------
          Net unrealized appreciation                                           $ 21,117,242
                                                                                ============


For financial reporting purposes net unrealized appreciation on investments was
$15,629,702 and cost of investments aggregated $363,665,851.

Purchases and sales of securities (excluding temporary cash investments) for the
six months ended October 31, 2015 aggregated $14,954,788 and $23,634,907,
respectively.

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.

The following is a summary of the inputs used as of October 31, 2015, in valuing
the Trust's investments.



------------------------------------------------------------------------------------
                                    Level 1   Level 2         Level 3   Total
------------------------------------------------------------------------------------
                                                            
Tax Exempt Obligations              $ --      $378,662,753    $ --      $378,662,753
Municipal Collateralized
   Debt Obligation                    --           632,800      --           632,800
------------------------------------------------------------------------------------
Total Investments in Securities     $ --      $379,295,553    $ --      $379,295,553
====================================================================================


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

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


Statement of Assets and Liabilities | 10/31/15 (unaudited)



                                                                           
ASSETS:
  Investments in securities, at value (cost $363,665,851)                     $ 379,295,553
  Cash                                                                           20,000,702
  Receivables --
     Interest receivable                                                          7,192,335
     Investment securities sold                                                     131,090
  Prepaid expenses                                                                    5,286
-------------------------------------------------------------------------------------------
        Total assets                                                          $ 406,624,966
===========================================================================================
LIABILITIES:
  Payables --
     Investment securities purchased                                          $   3,081,898
     Trustees' fees payable                                                           1,347
  Due to affiliates                                                                 203,447
  Administration fee payable                                                        107,928
  Accrued expenses                                                                  104,516
-------------------------------------------------------------------------------------------
        Total liabilities                                                     $   3,499,136
===========================================================================================
PREFERRED SHARES AT REDEMPTION VALUE:
  $25,000 liquidation value per share applicable to 4,040 shares, including
     dividends payable of $1,423                                              $ 101,001,423
-------------------------------------------------------------------------------------------
NET ASSETS APPLICABLE TO COMMON SHAREOWNERS:
  Paid-in capital                                                             $ 314,119,662
  Undistributed net investment income                                             3,688,522
  Accumulated net realized loss on investments                                  (31,313,479)
  Net unrealized appreciation on investments                                     15,629,702
-------------------------------------------------------------------------------------------
        Net assets applicable to common shareowners                           $ 302,124,407
===========================================================================================
NET ASSET VALUE PER COMMON SHARE:
  No par value (unlimited number of shares authorized)
     Based on $302,124,407 / 22,738,580 common shares                         $       13.29
===========================================================================================


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

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 21


Statement of Operations (unaudited)

For the Six Months Ended 10/31/15



                                                                              
INVESTMENT INCOME:
   Interest                                                                         $11,240,429
-----------------------------------------------------------------------------------------------
EXPENSES:
  Management fees                                                     $1,207,644
  Administrative expense                                                 125,030
  Transfer agent fees and expenses                                         7,658
  Shareholder communication expenses                                       8,553
  Auction agent fees                                                     126,886
  Custodian fees                                                           2,812
  Professional fees                                                       54,135
  Printing expenses                                                        4,981
  Trustees' fees                                                           7,135
  Pricing fees                                                            10,195
  Miscellaneous                                                           39,797
-----------------------------------------------------------------------------------------------
     Total expenses                                                                 $ 1,594,826
-----------------------------------------------------------------------------------------------
         Net investment income                                                      $ 9,645,603
-----------------------------------------------------------------------------------------------
REALIZED AND UNREALIZED GAIN (LOSS) ON INVESTMENTS:
   Net realized loss on investments                                   $ (218,522)
   Change in net unrealized depreciation on investments:                (383,019)
-----------------------------------------------------------------------------------------------
      Net realized and unrealized loss on investments                               $  (601,541)
-----------------------------------------------------------------------------------------------
DISTRIBUTIONS TO PREFERRED SHAREOWNERS FROM
NET INVESTMENT INCOME:                                                              $  (87,315)
-----------------------------------------------------------------------------------------------
   Net increase in net assets resulting from operations                             $ 8,956,747
===============================================================================================


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

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


Statements of Changes in Net Assets



--------------------------------------------------------------------------------------------
                                                              Six Months
                                                              Ended
                                                              10/31/15         Year Ended
                                                              (unaudited)      4/30/15
--------------------------------------------------------------------------------------------
                                                                         
FROM OPERATIONS:
Net investment income                                         $    9,645,603   $  20,537,755
Net realized gain (loss) on investments                             (218,522)        331,110
Change in net unrealized appreciation (depreciation)
   on investments                                                   (383,019)      3,313,660
Distributions to preferred shareowners from net
   investment income                                                 (87,315)       (128,802)
--------------------------------------------------------------------------------------------
       Net increase in net assets resulting from operations   $    8,956,747   $  24,053,723
--------------------------------------------------------------------------------------------
DISTRIBUTIONS TO COMMON SHAREOWNERS:
Net investment income and previously undistributed
   net investment income ($0.42 and $1.08 per
   share, respectively)                                       $   (9,550,204)  $ (24,502,438)
--------------------------------------------------------------------------------------------
      Total distributions to common shareowners               $   (9,550,204)  $ (24,502,438)
--------------------------------------------------------------------------------------------
FROM TRUST SHARE TRANSACTIONS:
Reinvestment of distributions                                 $           --   $   1,294,762
--------------------------------------------------------------------------------------------
   Net increase in net assets applicable to common
      shareowners from Trust share transactions               $           --   $   1,294,762
--------------------------------------------------------------------------------------------
      Net increase (decrease) in net assets applicable to
         common shareowners                                   $     (593,457)  $     846,047
--------------------------------------------------------------------------------------------
NET ASSETS APPLICABLE TO COMMON SHAREOWNERS:
Beginning of period                                              302,717,864     301,871,817
--------------------------------------------------------------------------------------------
End of period                                                 $  302,124,407   $ 302,717,864
--------------------------------------------------------------------------------------------
Undistributed net investment income                           $    3,688,522   $   3,680,438
============================================================================================


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

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 23


Financial Highlights



------------------------------------------------------------------------------------------------------------------------------------
                                                               Six Months
                                                               Ended         Year        Year        Year      Year        Year
                                                               10/31/15      Ended       Ended       Ended     Ended       Ended
                                                               (unaudited)   4/30/15     4/30/14     4/30/13   4/30/12     4/30/11
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                         
Per Share Operating Performance
Net asset value, beginning of period                           $  13.31      $  13.33    $  14.72    $  14.12  $  13.00    $  13.86
------------------------------------------------------------------------------------------------------------------------------------
Increase (decrease) from investment operations: (a)
  Net investment income                                        $   0.42      $   0.91    $   1.05    $   1.14  $   1.03    $   1.12
  Net realized and unrealized gain (loss) on investments          (0.02)         0.16       (1.29)       0.61      1.30       (0.89)
------------------------------------------------------------------------------------------------------------------------------------
Distributions to preferred shareowners from:
   Net investment income                                       $  (0.00)(h)  $  (0.01)   $  (0.01)   $  (0.01) $  (0.01)   $  (0.02)
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) from investment operations             $   0.40      $   1.06    $  (0.25)   $   1.74  $   2.32    $   0.21
------------------------------------------------------------------------------------------------------------------------------------
Distributions to common shareowners from:
  Net investment income and previously undistributed net
     investment income                                         $  (0.42)     $  (1.08)*  $  (1.14)*  $  (1.14) $  (1.20)*  $  (1.07)
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) in net asset value                     $  (0.02)     $  (0.02)   $  (1.39)   $   0.60  $   1.12    $  (0.86)
------------------------------------------------------------------------------------------------------------------------------------
Net asset value, end of period (b)                             $  13.29      $  13.31    $  13.33    $  14.72  $  14.12    $  13.00
------------------------------------------------------------------------------------------------------------------------------------
Market value, end of period (b)                                $  13.14      $  14.75    $  14.90    $  16.02  $  15.49    $  13.40
====================================================================================================================================
Total return at market value (c)                                  (7.91)%(e)     6.84%       1.10%      11.48%    25.95%       1.04%
Ratios to average net assets of common shareowners:
  Total expenses (d)                                               1.06%(f)      1.03%       1.04%       1.03%     1.08%       1.12%
  Net investment income before preferred share distributions       6.39%(f)      6.73%       7.89%       7.84%     7.50%       8.26%
  Preferred share distributions                                    0.06%(f)      0.04%       0.05%       0.08%     0.08%       0.14%
  Net investment income available to common shareowners            6.33%(f)      6.69%       7.84%       7.76%     7.42%       8.12%
Portfolio turnover                                                    4%           14%         19%         10%       11%         10%
Net assets of common shareowners, end of period (in thousands) $302,124      $302,718    $301,872    $332,193  $317,631    $291,053


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

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




------------------------------------------------------------------------------------------------------------------------------------
                                                                     Six Months
                                                                     Ended        Year      Year      Year       Year      Year
                                                                     10/31/15     Ended     Ended     Ended      Ended     Ended
                                                                     (unaudited)  4/30/15   4/30/14   4/30/13    4/30/12   4/30/11
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                         
Preferred shares outstanding (in thousands)                          $101,001     $101,001  $101,000  $101,000   $101,000  $101,000
Asset coverage per preferred share, end of period                    $ 99,784     $ 99,930  $ 99,721  $107,211   $103,623  $ 97,044
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  $ 25,000     $ 25,000  $ 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 decrease in
     distributions may have a negative effect on the market value of the Trust's
     shares.

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

(b)  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.

(c)  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.

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

(e)  Not annualized.

(f)  Annualized.

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

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

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

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 25


Notes to Financial Statements | 10/31/15 (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:

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.
     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 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

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


     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, 2015, 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.

     Discounts and premiums on purchase prices of debt securities are accreted
     or amortized, respectively, daily, into interest income on an effective
     yield 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 net taxable income and net realized capital gains, if any, to
     its shareowners. Therefore, no federal income tax provision is required. As
     of April 30, 2015, 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. Capital
     accounts within the financial statements are adjusted for permanent
     book/tax differences to reflect tax character, but are not adjusted for
     temporary differences.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 27


     The tax character of current year distributions payable to shareholders
     will be determined at the end of the current taxable year.

     The tax character of distributions paid to shareowners during the year
     ended April 30, 2015 was as follows:



     ---------------------------------------------------------------------------
                                                                            2015
     ---------------------------------------------------------------------------
                                                                 
     Distributions paid from:
     Tax exempt income                                               $23,767,247
     Ordinary income                                                     863,993
     ---------------------------------------------------------------------------
          Total                                                      $24,631,240
     ===========================================================================


     The following shows the components of distributable earnings (losses) on a
     federal income tax basis at April 30, 2015:



     ---------------------------------------------------------------------------
                                                                           2015
     ---------------------------------------------------------------------------
                                                                
     Distributable earnings:
     Undistributed ordinary income                                 $    530,667
     Capital loss carryforward                                      (34,791,020)
     Last year loss deferrals                                          (285,295)
     Dividends payable                                                     (769)
     Undistributed tax-exempt income                                  1,644,358
     Unrealized appreciation                                         21,500,261
     ---------------------------------------------------------------------------
          Total                                                    $(11,401,798)
     ===========================================================================


     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, book/tax
     differences 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.

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


     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 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.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 29


     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 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 six months
ended October 31, 2015, the net management fee was 0.60% (annualized) of the
Trust's average daily managed assets, which was equivalent to 0.80% (annualized)
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,
2015, $311,375 was payable to PIM related to management costs, administrative
costs and certain other services is included in "Due to affiliates" and
"Administration fee payable" on the Statement of Assets and Liabilities.

3. Transfer Agent

Prior to November 2, 2015, 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
(AST), provided substantially all transfer agent and shareowner services related
to the Trust's common shares at negotiated rates.

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

Effective November 2, 2015, AST serves as the transfer agent with respect to the
Trust's common shares. The Trust pays AST an annual fee, as agreed to from time
to time by the Trust and AST, for providing such services.

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


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 six months ended October 31, 2015, the
Trust expenses were not reduced under such arrangement.

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, 2015 and the year ended April 30, 2015 were as follows:



--------------------------------------------------------------------------------
                                                          10/31/15       4/30/15
--------------------------------------------------------------------------------
                                                                
Shares outstanding at beginning of period               22,738,580    22,646,773
Reinvestment of distributions                                   --        91,807
--------------------------------------------------------------------------------
Shares outstanding at end of period                     22,738,580    22,738,580
================================================================================


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, 2015, 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 0.088% to 0.275% during the six months ended
October 31, 2015.

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
ratios described in the prospectus for the APS.

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,

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


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 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

A monthly dividend was declared on November 3, 2015 from undistributed and
accumulated net investment income of $0.0700 per common share payable November
30, 2015, to common shareowners of record on November 18, 2015.

Subsequent  to October 31, 2015, dividends declared and paid on preferred shares
totaled  $18,488  in  aggregate  for  the two outstanding preferred share series
through December 9, 2015.

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


ADDITIONAL INFORMATION

During the period, 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.

PIM, the Trust's investment adviser, is currently an indirect, wholly owned
subsidiary of UniCredit. On November 11, 2015, UniCredit announced that it
signed a binding master agreement with Banco Santander and affiliates of Warburg
Pincus and General Atlantic (the "Private Equity Firms") with respect to Pioneer
Investments ("Pioneer") and Santander Asset Management ("SAM") (the
"Transaction").

The Transaction, as previously announced by UniCredit, will establish a holding
company, with the name Pioneer Investments, to be owned by UniCredit (50%) and
the Private Equity Firms (50% between them). The holding company will control
Pioneer's U.S. operations, including PIM. The holding company also will own
66.7% of Pioneer's and SAM's combined operations outside the U.S., while Banco
Santander will own directly the remaining 33.3% stake. The closing of the
Transaction is expected to happen in 2016, subject to certain regulatory and
other approvals.

Under the Investment Company Act of 1940, completion of the Transaction will
cause the Trust's investment advisory agreement with PIM to terminate.
Accordingly, the Trust's Board of Trustees will be asked to approve a new
investment advisory agreement. If approved by the Board, the Trust's new
investment advisory agreement will be submitted to the shareholders of the Trust
for their approval.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 33


Results of Shareholder Meeting

At the annual meeting of shareowners held on September 22, 2015, 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 two Class I Trustees and three Class III Trustees.



--------------------------------------------------------------------------------
Nominee                                    For                         Withheld
--------------------------------------------------------------------------------
                                                                 
Class I
Lisa M. Jones                              19,047,727                  1,153,345
Lorraine H. Monchak                        19,060,717                  1,140,555
Class III
Thomas J. Perna                            19,105,144                  1,096,128
Marguerite A. Piret*                            2,482                         65
Fred J. Ricciardi                          19,177,231                  1,024,041


*Elected by preferred shares only.

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


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 2015 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 2015 and July
2015. Supplemental contract review materials were provided to the Trustees in
September 2015. 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 2015, 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
2015, 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
2015.

At a meeting held on September 15, 2015, 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 approving the
renewal of the investment advisory agreement, the Trustees

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 35


considered various factors that they determined were relevant, including the
factors described below. 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 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 throughout the year 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' regular reviews and
discussions were factored into the Trustees' deliberations concerning the
renewal of the advisory agreement. The Trustees indicated that the Trust's
performance, when considered in connection with the various other factors, was
consistent with the renewal of the investment advisory agreement.

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


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. In all
quintile rankings referred to below, first quintile is most favorable to the
Trust's shareowners.

The Trustees considered that the Trust's management fee (based on managed
assets) for the most recent fiscal year 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 most recent fiscal year 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.

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.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 37


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 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.

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


Trustees, Officers and Service Providers

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

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

Transfer Agent
American Stock Transfer & Trust Company

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.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 39


                           This page for your notes.

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


                           This page for your notes.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 41


                           This page for your notes.

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


                           This page for your notes.

           Pioneer Municipal High Income Trust | Semiannual Report | 10/31/15 43


                           This page for your notes.

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


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) 2015 Pioneer Investments 19442-09-1215



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.

Not applicable.

(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.

Not applicable.


(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.

Not applicable.

(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.

Not applicable.

(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.

Not applicable.


(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.

Not applicable.

(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.

Not applicable.

(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 Trust's 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 report.



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 report.

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).

During the period covered by this report, there were no purchases
made by or on behalf of the registrant or any affiliated purchaser
as defined in Rule 10b-18(a)(3) under the Securities Exchange Act
of 1934 (the Exchange Act), of shares of the registrants equity
securities that are registered by the registrant pursuant to
Section 12 of the Exchange Act.



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 30, 2015


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 30, 2015


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

Date December 30, 2015

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