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