FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN 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 * Presidio Management Group X LLC   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) (Last) (First) (Middle) 2735 SAND HILL ROAD 3. Date of Earliest Transaction (Month/Day/Year) 09/09/2014 (Street) MENLO PARK, CA 94025 4. If Amendment, Date 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 (City) (State) (Zip) 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 Class A Common Stock 09/09/2014   C(1)   1,170,392 D (1) 1,170,392 I Directly owned by USVP X (3) Class A Common Stock 09/09/2014   C(1)   37,443 D (1) 37,443 I Directly owned by AFF X (3) Class B Common Stock 09/09/2014   C(1)   1,170,392 A (1) 1,170,392 I Directly owned by USVP X (3) Class B Common Stock 09/09/2014   C(1)   37,443 A (1) 37,443 I Directly owned by AFF X (3) Class B Common Stock 09/09/2014   J(2)   1,170,392 D (2) 0 I Directly owned by USVP X (3) Class B Common Stock 09/09/2014   J(2)   37,443 D (2) 0 I Directly owned by AFF X (3)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 Underlying Securities (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 of Derivative Security: 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

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Presidio Management Group X LLC 2735 SAND HILL ROAD MENLO PARK, CA 94025		X
US VENTURE PARTNERS X LP 2735 SAND HILL ROAD MENLO PARK, CA 94025		X
USVP X AFFILIATES LP 2735 SAND HILL ROAD MENLO PARK, CA 94025		X
FEDERMAN IRWIN 2735 SAND HILL ROAD MENLO PARK, CA 94025		X
KRAUSZ STEVEN M 2735 SAND HILL ROAD MENLO PARK, CA 94025		X
Lewis Richard W. 2735 SAND HILL ROAD MENLO PARK, CA 94025		X
Matteucci Paul A 2735 SAND HILL ROAD MENLO PARK, CA 94025		X
ROOT JONATHAN D 2735 SAND HILL ROAD MENLO PARK, CA 94025		X
Tansey Casey M 2735 SAND HILL ROAD MENLO PARK, CA 94025		X

Signatures

Michael P. Maher - Attorney-in-fact for each reporting person		09/10/2014
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	Each outstanding 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.
(2)	Prorata distribution in kind from the partnership without consideration to its limited partners.
(3)	The reported securities are owned directly by each of U.S. Venture Partners X, L.P. ("USVP X") and USVP X Affiliates Fund, L.P. ("AFF X") and together with USVP X and AFF X, the ("USVP X Funds"). Presidio Management Group X, LLC ("PMG X") is the general partner of each of USVP X and AFF X and may be deemed to have sole voting and dispositive power over the shares held by the USVP X Funds. PMG X and each of Irwin Federman, Steven M. Krausz, Richard W. Lewis, Paul A Matteucci, Jonathan D. Root and Casey M. Tansey, the managing members of PMG X, may be deemed to share voting and dispositive power over the reported shares. Such persons and entities disclaim beneficial ownership of shares held by the USVP X Funds, except to the extent of any proportionate pecuniary interest therein.

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