SECURITIES & EXCHANGE COMMISSION
                             Washington, D.C. 20549
                             ----------------------

                                 SCHEDULE 13G/A
                                 (Rule 13d-102)

             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
           TO RULES 13d-1(b), (c) AND (d) AND AMENDMENTS THERETO FILED
                              PURSUANT TO 13d-2(b)

                                (Amendment No.2)*

                         MAGELLAN HEALTH SERVICES, INC.
                                (Name of Issuer)

                     Common Stock, $0.01 par value per share
                         (Title of Class of Securities)


                                    559079207
                                 (CUSIP Number)


                                 April 30, 2009
             (Date of event which requires filing of this statement)


     Check the appropriate box to designate the rule pursuant to which this
Schedule is filed:

     [ ]  Rule 13d-1(b)
     [x]  Rule 13d-1(c)
     [ ]  Rule 13d-1(d)





                           (Page 1 of 20 Pages)
---------------
     *The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which would
alter the disclosures provided in a prior cover page.

     The information required in the remainder of this cover page shall not be
deemed to be "filed" for purposes of Section 18 of the Securities Exchange Act
of 1934 ("Act") or otherwise subject to the liabilities of that section of the
Act but shall be subject to all other provisions of the Act (however, see the
Notes).








CUSIP No. 559079207                 13G/A                Page 2 of 20 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            HealthCor Management, L.P.

            I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
            20-2893581
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [X]
                                                                  (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
            Delaware
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0

SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    3,400,000
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    3,400,000
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY
            OWNED BY EACH REPORTING PERSON
            3,400,000
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            9.63%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
            PN
-----------------------------------------------------------------------------
                    ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 559079207                 13G/A                Page 3 of 20 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            HealthCor Associates, LLC

            I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
            20-2891849
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [X]
                                                                  (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0

SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    3,400,000
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    3,400,000
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            3,400,000
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            9.63%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
            OO - limited liability company
-----------------------------------------------------------------------------
                    ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 559079207                 13G/A                Page 4 of 20 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            HealthCor Offshore, Ltd.

            I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [X]
                                                                  (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
            Cayman Islands
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0

SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    2,185,186
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,185,186
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY
            OWNED BY EACH REPORTING PERSON
            2,185,186
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            6.19%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
            OO - limited company
-----------------------------------------------------------------------------
                    ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 559079207                 13G/A                Page 5 of 20 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            HealthCor Offshore Master Fund, L.P.

            I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [X]
                                                                  (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
            Cayman Islands
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0

SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    2,185,186
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,185,186
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            2,185,186
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            6.19%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
            OO - limited company
-----------------------------------------------------------------------------
                    ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 559079207                 13G/A                Page 6 of 20 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            HealthCor Offshore GP, LLC

            I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [X]
                                                                  (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
            Cayman Islands
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0

SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    2,185,186
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,185,186
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            2,185,186
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            6.19%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
            OO - limited company
-----------------------------------------------------------------------------
                    ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 559079207                 13G/A                Page 7 of 20 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            HealthCor Hybrid Offshore, Ltd.

            I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [X]
                                                                  (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
            Cayman Islands
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0

SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    460,009
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    460,009
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            460,009
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            1.30%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
            OO - limited company
-----------------------------------------------------------------------------
                    ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 559079207                 13G/A                Page 8 of 20 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            HealthCor Hybrid Offshore Master Fund, L.P.

            I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [X]
                                                                  (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
            Cayman Islands
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0

SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    460,009
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    460,009
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            460,009
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            1.30%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
            OO - limited company
-----------------------------------------------------------------------------
                    ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 559079207                 13G/A                Page 9 of 20 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            HealthCor Hybrid Offshore GP, LLC

            I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [X]
                                                                  (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
            Cayman Islands
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0

SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    460,009
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    460,009
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            460,009
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            1.30%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
            OO - limited company
-----------------------------------------------------------------------------
                    ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 559079207                 13G/A                Page 10 of 20 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            HealthCor Group, LLC

            I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
            51-0551771
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [X]
                                                                  (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
            Delaware
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0

SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    3,400,000
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    3,400,000
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            3,400,000
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            9.63%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
            OO - limited liability company
-----------------------------------------------------------------------------
                    ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 559079207                 13G/A                Page 11 of 20 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            HealthCor Capital, L.P.

            I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
            51-0551770
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [X]
                                                                  (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
            Delaware
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0

SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    754,805
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    754,805
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            754,805
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            2.14%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
            PN
-----------------------------------------------------------------------------
                    ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 559079207                 13G/A                Page 12 of 20 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            HealthCor, L.P.

            I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
            20-3240266
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [X]
                                                                  (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
            Delaware
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0

SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    754,805
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    754,805
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            754,805
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            2.14%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
            PN
-----------------------------------------------------------------------------
                    ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 559079207                 13G/A                Page 13 of 20 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            Arthur Cohen

            I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [X]
                                                                  (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
            United States
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0

SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    3,400,000
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    3,400,000
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            3,400,000
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            9.63%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
            IN
-----------------------------------------------------------------------------
                    ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 559079207                13G/A                Page 14 of 20 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            Joseph Healey

            I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [X]
                                                                  (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
            United States
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    3,400,000
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    3,400,000
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            3,400,000
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            9.63%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
            IN
-----------------------------------------------------------------------------
                    ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 559079207                  13G/A                 Page 15 of 20 Pages


Item 1(a).     Name of Issuer:
               Magellan Health Services, Inc.

Item 1(b).     Address of Issuer's Principal Executive Offices:
               55 Nod Road, Avon, Connecticut 06001


Item 2(a, b, c).     Name of Person Filing:

               (i) HealthCor Management, L.P., a Delaware limited partnership;
               Carnegie Hall Tower, 152 West 57th Street, 47th Floor, New York,
               New York 10019;

               (ii) HealthCor Associates, LLC, a Delaware limited liability
               company, Carnegie Hall Tower, 152 West 57th Street, 47th Floor,
               New York, New York 10019;

               (iii) HealthCor Offshore, Ltd., a Cayman Islands limited company,
               Carnegie Hall Tower, 152 West 57th Street, 47th Floor, New York,
               New York 10019;

               (iv) HealthCor Offshore Master Fund, L.P., a Cayman Islands
               limited partnership, Carnegie Hall Tower, 152 West 57th Street,
               47th Floor, New York, New York 10019;

               (v) HealthCor Offshore GP, LLC, a Delaware limited liability
               company, Carnegie Hall Tower, 152 West 57th Street, 47th Floor,
               New York, New York 10019;

               (vi) HealthCor Hybrid Offshore, Ltd., a Cayman Islands limited
               company, Carnegie Hall Tower, 152 West 57th Street, 47th Floor,
               New York, New York 10019;

               (vii) HealthCor Hybrid Offshore Master Fund, L.P., a Cayman
               Islands limited partnership, Carnegie Hall Tower, 152 West 57th
               Street, 47th Floor, New York, New York 10019;

               (viii) HealthCor Hybrid Offshore GP, LLC, a Delaware limited
               liability company, Carnegie Hall Tower, 152 West 57th Street,
               47th Floor, New York, New York 10019;

               (ix) HealthCor Group, LLC, a Delaware limited liability company,
               Carnegie Hall Tower, 152 West 57th Street, 47th Floor, New York,
               New York 10019;

               (x) HealthCor Capital, L.P., a Delaware limited partnership,
               Carnegie Hall Tower, 152 West 57th Street, 47th Floor, New York,
               New York 10019;

               (xi) HealthCor, L.P., a Delaware limited partnership, Carnegie
               Hall Tower, 152 West 57th Street, 47th Floor, New York, New York
               10019;





CUSIP No. 559079207                  13G/A                 Page 16 of 20 Pages


               (xii) Joseph Healey; Carnegie Hall Tower, 152 West 57th Street,
               47th Floor, New York, New York 10019; and

               (xiii) Arthur Cohen, 12 South Main Street, #203 Norwalk, Ct
               06854.

               Both Mr. Healey and Mr. Cohen are United States citizens.

               The persons at (i) through (xiii) above are collectively referred
               to herein as the "Reporting Persons".

Item 2(d).     Title of Class of Securities: common stock, par value $.01 per
               share (the "Common Stock")

Item 2(e).     CUSIP Number:  559079207


Item 3.        Not applicable.

Item 4.   Ownership.

            The information required by Items 4(a) - (c) is set forth in Rows 5
            - 11 of the cover page for each Reporting Person hereto and is
            incorporated herein by reference for each such Reporting Person.

            Collectively, HealthCor, L.P., Healthcor Offshore Master Fund, L.P.
            and HealthCor Hybrid Offshore Master Fund, L.P. (each a "Fund" and
            together, the "Funds") are the beneficial owners of a total of
            3,400,000 shares of the Common Stock of the Issuer. By virtue of
            their position as feeder funds, HealthCor Offshore, Ltd. and
            HealthCor Hybrid Offshore, Ltd. may be deemed beneficial owners of
            the shares of Common Stock owned by HealthCor Offshore Master Fund,
            L.P., and HealthCor Hybrid Offshore Master Fund, L.P., respectively.

            HealthCor Offshore GP, LLC is the general partner of HealthCor
            Offshore Master Fund, L.P. Accordingly, HealthCor Offshore GP, LLC
            may be deemed to beneficially own the shares of Common Stock that
            are beneficially owned by HealthCor Offshore Master Fund, L.P.
            HealthCor Group, LLC is the general partner of HealthCor Offshore
            GP, LLC and, therefore, may be deemed to beneficially own the shares
            of Common Stock that are beneficially owned by HealthCor Offshore
            Master Fund, L.P.

            HealthCor Hybrid Offshore GP, LLC is the general partner of
            HealthCor Hybrid Offshore Master Fund, L.P. Accordingly, HealthCor
            Hybrid Offshore GP, LLC may be deemed to beneficially own the shares
            of Common Stock that are beneficially owned by HealthCor Hybrid
            Offshore Master Fund, L.P. HealthCor Group, LLC is the general
            partner of HealthCor Hybrid Offshore GP, LLC and, therefore, may be
            deemed to beneficially own the shares of Common Stock that are
            beneficially owned by HealthCor Hybrid Offshore Master Fund, L.P.

            By virtue of its position as the investment manager of the Funds,
            HealthCor Management, L.P. may be deemed a beneficial owner of all





CUSIP No. 559079207                13G/A                Page 17 of 20 Pages

            the shares of Common Stock owned by the Funds. HealthCor Associates,
            LLC is the general partner of HealthCor Management, L.P. and thus
            may also be deemed to beneficially own the shares of Common Stock
            that are beneficially owned by the Funds.

            HealthCor Group LLC is the general partner of HealthCor Capital,
            L.P., which is in turn the general partner of HealthCor, L.P.
            Accordingly, each of HealthCor Capital L.P. and HealthCor Group, LLC
            may be deemed to beneficially own the shares of Common Stock that
            are beneficially owned by HealthCor, L.P.

            As the Managers of HealthCor Associates, LLC, Arthur Cohen and
            Joseph Healey exercise both voting and investment power with respect
            to the shares of Common Stock reported herein, and therefore each
            may be deemed a beneficial owner of such Common Stock.

            Each of the Reporting Persons hereby disclaims any beneficial
            ownership of any such Shares in excess of their actual pecuniary
            interest therein.

            The Reporting Persons were originally passive investors who reported
            their Common Stock ownership on a form Schedule 13G filed with the
            Securities and Exchange Commission (the "SEC") on August 6, 2007, as
            thereafter amended. Believing that the Issuer was not maximizing
            shareholder value, the Reporting Persons sent the Issuer a letter on
            March 14, 2008, setting forth their strategy for improving such
            value, and thereby became obligated to file a Schedule 13D, which
            they filed on March 17, 2008. The Reporting Persons have
            discontinued such communications and have no intention to resume any
            such communications with the Issuer. Under the circumstances, the
            Reporting Persons have re-established their eligibility to file on
            Schedule 13G as passive investors.

Item 5.   Ownership of Five Percent or Less of a Class:

            If this statement is being filed to report the fact that as of the
            date hereof the reporting person has ceased to be the beneficial
            owner of more than five percent of the class of securities, check
            the following [ ].

Item 6.     Ownership of More than Five Percent on Behalf of Another Person.
            Not Applicable

Item 7.     Identification and Classification of the Subsidiary Which Acquired
            the Security Being Reported on by the Parent Holding Company.
            Not Applicable

Item 8.     Identification and Classification of Members of the Group.
            Not Applicable

Item 9.     Notice of Dissolution of Group.
            Not Applicable






CUSIP No. 559079207                13G/A                Page 18 of 20 Pages

Item 10.  Certification.

            By signing below I certify that, to the best of my knowledge and
            belief, the securities referred to above were not acquired and are
            not held for the purpose of or with the effect of changing or
            influencing the control of the issuer of the securities and were not
            acquired and are not held in connection with or as a participant in
            any transaction having that purpose or effect.

Exhibits:

Exhibit I: Joint Acquisition Statement, dated as of May 4, 2009.






CUSIP No. 559079207              13G/A                Page 19 of 20 Pages

                                    SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

DATED:  May 4, 2009

                  HEALTHCOR MANAGEMENT, L.P., for itself and
                  as manager on behalf of (i) HEALTHCOR OFFSHORE, LTD.
                  and (ii) HEALTHCOR HYBRID OFFSHORE, LTD.

                             By: HealthCor Associates, LLC, its general partner

                             By: /s/ John H. Coghlin
                             -------------------------------------
                             Name: John H. Coghlin
                             Title: General Counsel

                  HEALTHCOR CAPITAL, L.P., for itself and as general partner on
                  behalf of HEALTHCOR L.P.

                             By: HealthCor Group, LLC, its general partner

                             By: /s/ John H. Coghlin
                             -------------------------------------
                             Name: John H. Coghlin
                             Title: General Counsel

                  HEALTHCOR OFFSHORE GP, LLC, for itself and as general partner
                  of behalf of HEALTHCOR OFFSHORE MASTER FUND, L.P.


                             By: HealthCor Group, LLC, its general partner

                             By: /s/ John H. Coghlin
                             -------------------------------------
                             Name:  John H. Coghlin
                             Title:  General Counsel

                  HEALTHCOR HYBRID OFFSHORE GP, LLC, for itself and as general
                  partner of behalf of HEALTHCOR HYBRID OFFSHORE MASTER FUND,
                  L.P.

                             By: HealthCor Group, LLC, its general partner

                             By: /s/ John H. Coghlin
                             -------------------------------------
                             Name:  John H. Coghlin
                             Title:  General Counsel

                  HEALTHCOR ASSOCIATES, LLC

                             By: /s/ John H. Coghlin
                             -------------------------------------
                             Name: John H. Coghlin
                             Title: General Counsel




CUSIP No. 559079207                13G/A                Page 20 of 20 Pages


                  HEALTHCOR GROUP, LLC

                             By: /s/ John H. Coghlin
                             -------------------------------------
                             Name: John H. Coghlin
                             Title: General Counsel

                  JOSEPH HEALEY, Individually

                             /s/ Joseph Healey
                             -----------------------------------

                  ARTHUR COHEN, Individually

                             /s/ Arthur Cohen
                             -----------------------------------









                                    EXHIBIT 1

              JOINT ACQUISITION STATEMENT PURSUANT TO RULE 13d-1(k)

         The undersigned acknowledge and agree that the foregoing statement on
Schedule 13G/A is filed on behalf of each of the undersigned and that all
subsequent amendments to this statement on Schedule 13G/A shall be filed on
behalf of each of the undersigned without the necessity of filing additional
joint acquisition statements. The undersigned acknowledge that each shall be
responsible for the completeness and accuracy of the information concerning the
others, except to the extent that he or it knows or has reason to believe that
such information is inaccurate.

Dated:   May 4, 2009


                  HEALTHCOR MANAGEMENT, L.P., for itself and
                  as manager on behalf of (i) HEALTHCOR OFFSHORE, LTD.
                  and (ii) HEALTHCOR HYBRID OFFSHORE, LTD.


                             By: HealthCor Associates, LLC, its general partner

                             By: /s/ John H. Coghlin
                             -------------------------------------
                             Name: John H. Coghlin
                             Title: General Counsel

                  HEALTHCOR CAPITAL, L.P., for itself and as general partner on
                  behalf of HEALTHCOR L.P.


                             By: HealthCor Group, LLC, its general partner

                             By: /s/ John H. Coghlin
                             -------------------------------------
                             Name: John H. Coghlin
                             Title: General Counsel

                  HEALTHCOR OFFSHORE GP, LLC, for itself and as general partner
                  of behalf of HEALTHCOR OFFSHORE MASTER FUND, L.P.


                             By: HealthCor Group, LLC, its general partner

                             By: /s/ John H. Coghlin
                             -------------------------------------
                             Name:  John H. Coghlin
                             Title:  General Counsel

                  HEALTHCOR HYBRID OFFSHORE GP, LLC, for itself and as general
                  partner of behalf of HEALTHCOR HYBRID OFFSHORE MASTER FUND,
                  L.P.


                             By: HealthCor Group, LLC, its general partner

                             By: /s/ John H. Coghlin
                             -------------------------------------
                             Name:  John H. Coghlin
                             Title:  General Counsel


                  HEALTHCOR ASSOCIATES, LLC

                             By: /s/ John H. Coghlin
                             -------------------------------------
                             Name: John H. Coghlin
                             Title: General Counsel

                  HEALTHCOR GROUP, LLC

                             By: /s/ John H. Coghlin
                             -------------------------------------
                             Name: John H. Coghlin
                             Title: General Counsel

                  JOSEPH HEALEY, Individually

                             /s/ Joseph Healey
                             -----------------------------------

                  ARTHUR COHEN, Individually

                             /s/ Arthur Cohen
                             -----------------------------------