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
	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* MAVERICK CAPITAL LTD (Last) (First) (Middle) 300 CRESCENT COURT 18TH FLOOR (Street) DALLAS TX 75201 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol CASTLIGHT HEALTH, INC. [ CSLT ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 03/19/2014
	4. If Amendment, Date of Original Filed (Month/Day/Year) 03/21/2014	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

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
Series A Preferred Stock	$0(1)	03/19/2014		C			520,245	(1)	(2)	Class A Common Stock	520,245	$0(1)	0	I	Maverick Fund II, Ltd.(3)
Series A-1 Preferred Stock	$0(1)	03/19/2014		C			1,037,788	(1)	(2)	Class A Common Stock	1,037,788	$0(1)	0	I	See footnote(3)(4)
Series B Preferred Stock	$0(1)	03/19/2014		C			2,590,090	(1)	(2)	Class A Common Stock	2,590,090	$0(1)	0	I	See footnote(3)(5)
Series C Preferred Stock	$0(1)	03/19/2014		C			3,162,163	(1)	(2)	Class A Common Stock	3,162,163	$0(1)	0	I	Maverick USA Private Investments, LLC(3)
Series D Preferred Stock	$0(1)	03/19/2014		C			345,064	(1)	(2)	Class A Common Stock	345,064	$0(1)	0	I	Maverick Fund II, Ltd.(3)
Class A Common Stock	$0(1)(2)	03/19/2014		C		7,655,350(1)		(2)	(2)	Class B Common Stock	7,655,350	$0(2)	7,733,386	I	See footnote(3)

1. Name and Address of Reporting Person* MAVERICK CAPITAL LTD (Last) (First) (Middle) 300 CRESCENT COURT 18TH FLOOR (Street) DALLAS TX 75201 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MAVERICK CAPITAL MANAGEMENT LLC (Last) (First) (Middle) 300 CRESCENT COURT 18TH FLOOR (Street) DALLAS TX 75201 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* AINSLIE LEE S III (Last) (First) (Middle) 767 FIFTH AVENUE 11TH FLOOR (Street) NEW YORK NY 10153 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. In connection with the consummation of Castlight Health Inc.'s initial public offering, each share of convertible preferred stock automatically converted into one (1) share of Class A common stock for no additional consideration. All shares of Class A common stock issued upon conversion were aggregated for purposes of this Report.

2. Each share of Class A common stock is convertible at any time at the option of the holder, into one share of Class B common stock at any time after Castlight Health Inc.'s initial public offering.

3. Maverick Capital, Ltd. ("Maverick Capital") is a registered investment adviser under the Investment Advisers Act of 1940, as amended, and acts as the investment manager for each of the portfolio funds that directly hold the reported securities. Maverick Capital Management, LLC ("Maverick") is the general partner of Maverick Capital. Lee S. Ainslie III is the manager of Maverick who is granted sole investment decision pursuant to Maverick's limited liability company regulations. Each reporting owner disclaims beneficial ownership of the reported securities except to the extent of its pecuniary interest therein.

4. Maverick USA Private Investments, LLC held 833,333 shares of Series A-1 preferred stock; and Maverick Fund II, Ltd. held 204,455 shares of Series A-1 preferred stock.

5. Maverick Fund Private Investments, Ltd. held 2,252,252 shares of Series B preferred stock; and Maverick USA Private Investments, LLC held 337,838 shares of Series B preferred stock.

	/s/ John T. McCafferty, Attorney-in-Fact	03/26/2014
	/s/ John T. McCafferty, Attorney-in-Fact	03/26/2014
	/s/ John T. McCafferty, Attorney-in-Fact	03/26/2014
	** Signature of Reporting Person	Date
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