FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person *   MAVERICK CAPITAL LTD 2. Date of Event Requiring Statement (Month/Day/Year) 03/13/2014 3. Issuer Name and Ticker or Trading Symbol CASTLIGHT HEALTH, INC. [CSLT] (Last) (First) (Middle) 300 CRESCENT COURT, 18TH FLOOR 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) DALLAS, TX 75201 6. Individual or Joint/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Class A Common Stock	  (2)	  (2)	Class B Common Stock	78,036	$ 0 (2)	I	Maverick Fund II, Ltd. (1)
Series A Preferred Stock	  (3)	  (3)	Class A Common Stock	520,245	$ 0 (3)	I	Maverick Fund II, Ltd. (1)
Series A-1 Preferred Stock	  (3)	  (3)	Class A Common Stock	1,037,788	$ 0 (3)	I	See footnote (1) (4)
Series B Preferred Stock	  (3)	  (3)	Class A Common Stock	2,590,090	$ 0 (3)	I	See footnote (1) (5)
Series C Preferred Stock	  (3)	  (3)	Class A Common Stock	3,162,163	$ 0 (3)	I	Maverick USA Private Investments, LLC (1)
Series D Preferred Stock	  (3)	  (3)	Class A Common Stock	345,064	$ 0 (3)	I	Maverick Fund II, Ltd. (1)
Stock Option	  (6)	03/12/2024	Class B Common Stock	25,000	$ 11	I	See footnote (7)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
MAVERICK CAPITAL LTD 300 CRESCENT COURT 18TH FLOOR DALLAS, TX 75201	Â	  X	Â	Â
MAVERICK CAPITAL MANAGEMENT LLC 300 CRESCENT COURT 18TH FLOOR DALLAS, TX 75201	Â	  X	Â	Â
AINSLIE LEE S III 767 FIFTH AVENUE 11TH FLOOR NEW YORK, NY 10153	Â	  X	Â	Â

Signatures

/s/ John T. McCafferty, Attorney-in-Fact		03/13/2014
**Signature of Reporting Person		Date
/s/ John T. McCafferty, Attorney-in-Fact		03/13/2014
**Signature of Reporting Person		Date
/s/ John T. McCafferty, Attorney-in-Fact		03/13/2014
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(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).
(1)	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.
(2)	Each share of Class A common stock is convertible into one share of Class B common stock at any time after Castlight Health Inc.'s March 13, 2014 offering.
(3)	Each share of Series A preferred stock, Series B preferred stock, Series A-1 preferred stock, Series C preferred stock and Series D preferred stock will convert automatically into one share of Class A common stock upon the completion of Castlight Health Inc.'s March 13, 2014 offering.
(4)	Maverick USA Private Investments, LLC holds 833,333 shares of Series A-1 preferred stock; and Maverick Fund II, Ltd. holds 204,455 shares of Series A-1 preferred stock.
(5)	Maverick Fund Private Investments, Ltd. holds 2,252,252 shares of Series B preferred stock; and Maverick USA Private Investments, LLC holds 337,838 shares of Series B preferred stock.
(6)	This stock option vests in 12 equal monthly installments beginning one month after the vesting commencement date, until such time as the option is 100% vested, subject to the continuing service of David B. Singer on Castlight Health, Inc.'s Board of Directors on each vesting date.
(7)	This stock option is held by David B. Singer for the benefit of Maverick Fund, L.D.C., Maverick Fund USA, Ltd. and Maverick Fund II, Ltd. Mr. Singer is an employee of an affiliate of Maverick Capital, Ltd.

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