SECURITIES & EXCHANGE COMMISSION
                             Washington, D.C. 20549
                             ----------------------
                                  SCHEDULE 13G
                                 (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 RULE 13d-2

                               (Amendment No. 6)*

                         Magellan Health Services, Inc.
                                (Name of Issuer)

                     Common Stock, $.01 Par Value Per Share
                         (Title of Class of Securities)


                                   559079207
                                 (CUSIP Number)


                               December 31, 2011
            (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 18 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                Page 2 of 18 Pages


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


-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                            (see instructions)
                                                                  (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
                    2,130,500
OWNED BY       --------------------------------------------------------------

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

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,130,500
-----------------------------------------------------------------------------
     (9)     AGGREGATE AMOUNT BENEFICIALLY OWNED
             BY EACH REPORTING PERSON
             2,130,500
-----------------------------------------------------------------------------
     (10)    CHECK BOX IF THE AGGREGATE AMOUNT
             IN ROW (9) EXCLUDES CERTAIN SHARES(see instructions)       [ ]
-----------------------------------------------------------------------------
     (11)    PERCENT OF CLASS REPRESENTED
             BY AMOUNT IN ROW (9)
             7.48%
-----------------------------------------------------------------------------
     (12)    TYPE OF REPORTING PERSON (see instructions)
             PN
-----------------------------------------------------------------------------



CUSIP No. 559079207                13G                Page 3 of 18 Pages


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


-----------------------------------------------------------------------------
        (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                            (see instructions)
                                                                  (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
                            2,130,500
OWNED BY       --------------------------------------------------------------

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

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                      2,130,500
-----------------------------------------------------------------------------
     (9)     AGGREGATE AMOUNT BENEFICIALLY OWNED
             BY EACH REPORTING PERSON
             2,130,500
-----------------------------------------------------------------------------
     (10)    CHECK BOX IF THE AGGREGATE AMOUNT
             IN ROW (9) EXCLUDES CERTAIN SHARES(see instructions)       [ ]
-----------------------------------------------------------------------------
     (11)    PERCENT OF CLASS REPRESENTED
             BY AMOUNT IN ROW (9)
             7.48%
-----------------------------------------------------------------------------
     (12)    TYPE OF REPORTING PERSON (see instructions)
             OO - limited liability company
-----------------------------------------------------------------------------



CUSIP No. 559079207                13G                Page 4 of 18 Pages



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

-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP(see instructions)
                                                                  (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
                    1,465,768
OWNED BY       --------------------------------------------------------------

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

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    1,465,768
-----------------------------------------------------------------------------
     (9)     AGGREGATE AMOUNT BENEFICIALLY OWNED
             BY EACH REPORTING PERSON
             1,465,768
-----------------------------------------------------------------------------
     (10)    CHECK BOX IF THE AGGREGATE AMOUNT
             IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions)       [ ]
-----------------------------------------------------------------------------
     (11)    PERCENT OF CLASS REPRESENTED
             BY AMOUNT IN ROW (9)
             5.15%
-----------------------------------------------------------------------------
     (12)    TYPE OF REPORTING PERSON (see instructions)
             PN
-----------------------------------------------------------------------------



CUSIP No. 559079207                13G                Page 5 of 18 Pages


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


-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP(see instructions)
                                                                  (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
                    1,465,768
OWNED BY       --------------------------------------------------------------

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

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    1,465,768
-----------------------------------------------------------------------------
     (9)     AGGREGATE AMOUNT BENEFICIALLY OWNED
             BY EACH REPORTING PERSON
             1,465,768
-----------------------------------------------------------------------------
     (10)    CHECK BOX IF THE AGGREGATE AMOUNT
             IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions)        [ ]
-----------------------------------------------------------------------------
     (11)    PERCENT OF CLASS REPRESENTED
             BY AMOUNT IN ROW (9)
             5.15%
-----------------------------------------------------------------------------
     (12)    TYPE OF REPORTING PERSON (see instructions)
             OO - limited liability company
-----------------------------------------------------------------------------

CUSIP No. 559079207                13G                Page 6 of 18 Pages


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


-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP(see instructions)
                                                                  (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
                    89,058
OWNED BY       --------------------------------------------------------------

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

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    89,058
-----------------------------------------------------------------------------
     (9)     AGGREGATE AMOUNT BENEFICIALLY OWNED
             BY EACH REPORTING PERSON
             89,058
-----------------------------------------------------------------------------
     (10)    CHECK BOX IF THE AGGREGATE AMOUNT
             IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions)        [ ]
-----------------------------------------------------------------------------
     (11)    PERCENT OF CLASS REPRESENTED
             BY AMOUNT IN ROW (9)
             0.31%
-----------------------------------------------------------------------------
     (12)    TYPE OF REPORTING PERSON (see instructions)
             PN
-----------------------------------------------------------------------------



CUSIP No. 559079207                13G                Page 7 of 18 Pages


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


-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP(see instructions)
                                                                  (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
                    89,058
OWNED BY       --------------------------------------------------------------

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

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    89,058
-----------------------------------------------------------------------------
     (9)     AGGREGATE AMOUNT BENEFICIALLY OWNED
             BY EACH REPORTING PERSON
             89,058
-----------------------------------------------------------------------------
     (10)    CHECK BOX IF THE AGGREGATE AMOUNT
             IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions)        [ ]
-----------------------------------------------------------------------------
     (11)    PERCENT OF CLASS REPRESENTED
             BY AMOUNT IN ROW (9)
             0.31%
-----------------------------------------------------------------------------
     (12)    TYPE OF REPORTING PERSON (see instructions)
             OO - limited liability company
-----------------------------------------------------------------------------



CUSIP No. 559079207                13G                Page 8 of 18 Pages


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


-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP(see instructions)
                                                                  (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
                    2,130,500
OWNED BY       --------------------------------------------------------------

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

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,130,500
-----------------------------------------------------------------------------
     (9)     AGGREGATE AMOUNT BENEFICIALLY OWNED
             BY EACH REPORTING PERSON
             2,130,500
-----------------------------------------------------------------------------
     (10)    CHECK BOX IF THE AGGREGATE AMOUNT
             IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions)        [ ]
-----------------------------------------------------------------------------
     (11)    PERCENT OF CLASS REPRESENTED
             BY AMOUNT IN ROW (9)
             7.48%
-----------------------------------------------------------------------------
     (12)    TYPE OF REPORTING PERSON (see instructions)
             OO - limited liability company
-----------------------------------------------------------------------------



CUSIP No. 559079207                13G                Page 9 of 18 Pages


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


-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP(see instructions)
                                                                  (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
                    575,674
OWNED BY       --------------------------------------------------------------

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

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    575,674
-----------------------------------------------------------------------------
     (9)     AGGREGATE AMOUNT BENEFICIALLY OWNED
             BY EACH REPORTING PERSON
             575,674
-----------------------------------------------------------------------------
     (10)    CHECK BOX IF THE AGGREGATE AMOUNT
             IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions)        [ ]
-----------------------------------------------------------------------------
     (11)    PERCENT OF CLASS REPRESENTED
             BY AMOUNT IN ROW (9)
             2.02%
-----------------------------------------------------------------------------
        (12)       TYPE OF REPORTING PERSON (see instructions)
             PN
-----------------------------------------------------------------------------



CUSIP No. 559079207                13G                Page 10 of 18 Pages


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


-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP(see instructions)
                                                                  (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
                    575,674
OWNED BY       --------------------------------------------------------------

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

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    575,674
-----------------------------------------------------------------------------
     (9)     AGGREGATE AMOUNT BENEFICIALLY OWNED
             BY EACH REPORTING PERSON
             575,674
-----------------------------------------------------------------------------
     (10)    CHECK BOX IF THE AGGREGATE AMOUNT
             IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions)        [ ]
-----------------------------------------------------------------------------
     (11)    PERCENT OF CLASS REPRESENTED
             BY AMOUNT IN ROW (9)
             2.02%
-----------------------------------------------------------------------------
        (12)       TYPE OF REPORTING PERSON (see instructions)
             PN
-----------------------------------------------------------------------------

CUSIP No. 559079207                13G                Page 11 of 18 Pages


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

-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP(see instructions)
                                                                  (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
                    2,130,500
OWNED BY       --------------------------------------------------------------

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

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,130,500
-----------------------------------------------------------------------------
     (9)     AGGREGATE AMOUNT BENEFICIALLY OWNED
             BY EACH REPORTING PERSON
             2,130,500
-----------------------------------------------------------------------------
     (10)    CHECK BOX IF THE AGGREGATE AMOUNT
             IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions)        [ ]
-----------------------------------------------------------------------------
     (11)    PERCENT OF CLASS REPRESENTED
             BY AMOUNT IN ROW (9)
             7.48%
-----------------------------------------------------------------------------
     (12)    TYPE OF REPORTING PERSON (see instructions)
             IN
-----------------------------------------------------------------------------



CUSIP No. 559079207                13G                Page 12 of 18 Pages


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


-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP(see instructions)
                                                                  (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
                    2,130,500
OWNED BY       --------------------------------------------------------------

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

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,130,500
-----------------------------------------------------------------------------
     (9)     AGGREGATE AMOUNT BENEFICIALLY OWNED
             BY EACH REPORTING PERSON
             2,130,500
-----------------------------------------------------------------------------
     (10)    CHECK BOX IF THE AGGREGATE AMOUNT
             IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions)        [ ]
-----------------------------------------------------------------------------
     (11)    PERCENT OF CLASS REPRESENTED
             BY AMOUNT IN ROW (9)
             7.48%
-----------------------------------------------------------------------------
     (12)    TYPE OF REPORTING PERSON (see instructions)
             IN
-----------------------------------------------------------------------------



CUSIP No. 559079207                13G                 Page 13 of 18 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, CT 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, 43rd Floor, New
                 York, New York 10019;

                 (ii) HealthCor Associates, LLC, a Delaware limited liability
                 company, Carnegie Hall Tower, 152 West 57th Street, 43rd Floor,
                 New York, New York 10019;

                 (iii) HealthCor Offshore Master Fund, L.P., a Cayman Islands
                 limited partnership, Carnegie Hall Tower, 152 West 57th Street,
                 43rd Floor, New York, New York 10019;

                 (iv) HealthCor Offshore GP, LLC, a Delaware limited liability
                 company, Carnegie Hall Tower, 152 West 57th Street, 43rd Floor,
                 New York, New York 10019;

                 (v) HealthCor Hybrid Offshore Master Fund, L.P., a Cayman
                 Islands limited partnership, Carnegie Hall Tower, 152 West 57th
                 Street, 43rd Floor, New York, New York 10019;

                 (vi) HealthCor Hybrid Offshore GP, LLC, a Delaware limited
                 liability company, Carnegie Hall Tower, 152 West 57th Street,
                 43rd Floor, New York, New York 10019;

                 (vii) HealthCor Group, LLC, a Delaware limited liability
                 company, Carnegie Hall Tower, 152 West 57th Street, 43rd Floor,
                 New York, New York 10019;

                 (viii) HealthCor Capital, L.P., a Delaware limited partnership,
                 Carnegie Hall Tower, 152 West 57th Street, 43rd Floor, New
                 York, New York 10019;

                 (ix) HealthCor, L.P., a Delaware limited partnership, Carnegie
                 Hall Tower, 152 West 57th Street, 43rd Floor, New York, New
                 York 10019;



CUSIP No. 559079207                13G                 Page 14 of 18 Pages


                 (x) Joseph Healey, Carnegie Hall Tower, 152 West 57th Street,
                 43rd Floor, New York, New York 10019; and

                 (xi) 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 (xi) above are collectively referred
                 to herein as the "Reporting Persons".

Item 2(d).       Title of Class of Securities: Common Stock, $.01 Par Value 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 2,130,500 shares of the Common Stock of the Issuer.

                 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.




CUSIP No. 559079207                13G                Page 15 of 18 Pages


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


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.
                 See Exhibit 1

Item 9.          Notice of Dissolution of Group.
                 Not Applicable



CUSIP No. 559079207                13G                Page 16 of 18 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 February 9, 2012.




CUSIP No. 559079207                13G                Page 17 of 18 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:  February 9, 2012

                 HEALTHCOR MANAGEMENT, L.P.

                                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                Page 18 of 18 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 is filed on behalf of each of the undersigned and that all
subsequent amendments to this statement on Schedule 13G 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:   February 9, 2012


                 HEALTHCOR MANAGEMENT, L.P.

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