SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
X	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* HealthCor Management, L.P. (Last) (First) (Middle) 152 W. 57TH STREET, 43RD FLOOR (Street) NEW YORK NY 10019 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol MAGELLAN HEALTH SERVICES INC [ MGLN ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner Officer (give title below) X Other (specify below) Former 10% owner
	3. Date of Earliest Transaction (Month/Day/Year) 12/06/2011
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock, $0.001 par value per share	12/06/2011		S		500,000	D	$48.534	2,500,000	I	See Footnote(1)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* HealthCor Management, L.P. (Last) (First) (Middle) 152 W. 57TH STREET, 43RD FLOOR (Street) NEW YORK NY 10019 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Former 10% owner

1. Name and Address of Reporting Person* HealthCor Associates, LLC (Last) (First) (Middle) 152 W. 57TH STREET, 43RD FLOOR (Street) NEW YORK NY 10019 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Former 10% owner

1. Name and Address of Reporting Person* HealthCor Hybrid Offshore Master Fund, L.P. (Last) (First) (Middle) 152 W. 57TH STREET, 43RD FLOOR (Street) NEW YORK NY 10019 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Former 10% owner

1. Name and Address of Reporting Person* HealthCor Offshore GP, LLC (Last) (First) (Middle) 152 W. 57TH STREET, 43RD FLOOR (Street) NEW YORK NY 10019 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Former 10% owner

1. Name and Address of Reporting Person* HealthCor Group, LLC (Last) (First) (Middle) 152 W. 57TH STREET, 43RD FLOOR (Street) NEW YORK NY 10019 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Former 10% owner

1. Name and Address of Reporting Person* HealthCor Capital, L.P. (Last) (First) (Middle) 152 W. 57TH STREET, 43RD FLOOR (Street) NEW YORK NY 10019 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Former 10% owner

1. Name and Address of Reporting Person* HEALTHCOR L P (Last) (First) (Middle) 152 W. 57TH STREET, 43RD FLOOR (Street) NEW YORK NY 10019 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Former 10% owner

1. Name and Address of Reporting Person* HealthCor Offshore Master Fund, L.P. (Last) (First) (Middle) 152 W. 57TH STREET, 43RD FLOOR (Street) NEW YORK NY 10019 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Former 10% owner

1. Name and Address of Reporting Person* HealthCor Hybrid Offshore GP, LLC (Last) (First) (Middle) 152 W. 57TH STREET, 43RD FLOOR (Street) NEW YORK NY 10019 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Former 10% owner

Explanation of Responses:

1. HealthCor Management, L.P. is the investment manager of Healthcor, L.P., HealthCor Offshore Master Fund, L.P., and HealthCor Hybrid Offshore Master Fund, L.P., which are the direct beneficial owners of the securities reported herein. The general partner of HealthCor, L.P. is Healthcor Capital, L.P. and the general partner of HealthCor Capital, L.P. is HealthCor Group, LLC. The general partner of Healthcor Offshore Master Fund, L.P. is HealthCor Offshore GP, LLC. The general partner of HealthCor Hybrid Offshore Master Fund, L.P. is HealthCor Hybrid Offshore GP, LLC. HealthCor Group, LLC is the general partner of HealthCor Offshore GP, LLC and HealthCor Hybrid Offshore GP, LLC. HealthCor Associates, LLC is the general partner of HealthCor Management, L.P. and Arthur Cohen and Joseph Healey are the managers of HealthCor Associates, LLC. Each of the reporting persons disclaims beneficial ownership of any and all such securities in excess of its or his own actual pecuniary interest.

Remarks:

HealthCor Management, L.P. is the designated filer on behalf of the reporting persons listed on Exhibit 99.1, attached hereto. Due to the number of reporting persons, this is one of two Form 4's filed relating to the same securities.

	HealthCor Management, L.P., by HealthCor Associates, LLC, its general partner, By: /s/ John H. Coghlin , General Counsel	12/07/2011
	HealthCor Associates, LLC, By: /s/ John H. Coghlin, General Counsel	12/07/2011
	HealthCor Hybrid Offshore GP, LLC, for itself and as general partner on behalf of HealthCor Hybrid Offshore Master Fund, L.P., by HealthCor Group, LLC, its general partner, By: /s/ John H. Coghlin , General Counsel	12/07/2011
	HealthCor Offshore GP, LLC, for itself and as general partner of on behalf of HealthCor Offshore Master Fund, L.P., by HealthCor Group, LLC, its general partner, By: /s/ John H. Coghlin , General Counsel	12/07/2011
	HealthCor Group, LLC, By: /s/ John H. Coghlin, General Counsel	12/07/2011
	HealthCor Capital L.P., for itself and as manager on behalf of HealthCor L.P., by HealthCor Group, LLC, its general partner, By: /s/ John H. Coghlin, General Counsel	12/07/2011
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.