Ownership Submission
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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(Print or Type Responses)
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)
03/19/2014
(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 03/19/2014   C   2,321,233 A (1) 2,340,784 I Directly owned by USVP X (4)
Class A Common Stock 03/19/2014   C   74,261 A (1) 74,886 I Directly owned by AFF X (4)

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
Series A Preferred Stock (1) 03/19/2014   C     130,339   (2)   (3) Class A Common Stock 130,339 (1) 0 I Directly owned by USVP X (4)
Series A1 Preferred Stock (1) 03/19/2014   C     51,223   (2)   (3) Class A Common Stock 51,223 (1) 0 I Directly owned by USVP X (4)
Series C Preferred Stock (1) 03/19/2014   C     1,649,919   (2)   (3) Class A Common Stock 1,649,919 (1) 0 I Directly owned by USVP X (4)
Series D Preferred Stock (1) 03/19/2014   C     489,752   (2)   (3) Class A Common Stock 489,752 (1) 0 I Directly owned by USVP X (4)
Series A Preferred Stock (1) 03/19/2014   C     4,170   (2)   (3) Class A Common Stock 4,170 (1) 0 I Directly owned by AFF X (4)
Series A1 Preferred Stock (1) 03/19/2014   C     1,639   (2)   (3) Class A Common Stock 1,639 (1) 0 I Directly owned by AFF X (4)
Series C Preferred Stock (1) 03/19/2014   C     52,784   (2)   (3) Class A Common Stock 52,784 (1) 0 I Directly owned by AFF X (4)
Series D Preferred Stock (1) 03/19/2014   C     15,668   (2)   (3) Class A Common Stock 15,668 (1) 0 I Directly owned by AFF X (4)

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   03/20/2014
**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) The Series A, Series A1, Series C and Series D Convertible Preferred Stock will automatically convert into Class A Common Stock on a one-for-one basis immediately prior to the completion of the Issuer's initial public offering on March 13, 2014.
(2) The securities are immediately convertible.
(3) The expiration date is not relevant to the conversion of these securities.
(4) 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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