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 * Colella Giovanni M.   2. Issuer Name and Ticker or Trading Symbol CASTLIGHT HEALTH, INC. [CSLT] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner _____ Officer (give title below) __X__ Other (specify below) Executive Chairman (Last) (First) (Middle) C/O CASTLIGHT HEALTH, INC., 150 SPEAR ST., SUITE 400 3. Date of Earliest Transaction (Month/Day/Year) 10/25/2017 (Street) SAN FRANCISCO, CA 94105 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ 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 B Common Stock 10/25/2017   M(1)   64,313 A $ 0 143,219 D   Class B Common Stock 10/25/2017   M(2)   190,625 A $ 0 333,844 D

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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

Restricted Stock Units

$ 0 (3)

10/25/2017

M(1)

64,313

(1)

(1)

Class B Common Stock

64,313

$ 0

0

D

Restricted Stock Units

$ 0 (3)

10/25/2017

M(2)

190,625

(2)

(2)

Class B Common Stock

190,625

$ 0

0

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Colella Giovanni M. C/O CASTLIGHT HEALTH, INC. 150 SPEAR ST., SUITE 400 SAN FRANCISCO, CA 94105	X	X		Executive Chairman

Signatures

/s/ Jennifer Chaloemtiarana, by power of attorney		10/27/2017
**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)	In connection with the Reporting Person's retirement from the Board of the Company on October 25, 2017, the Board determined to accelerate the remaining 64,313 unvested shares of restricted stock units ("RSUs") initially granted to the Reporting Person on June 17, 2015, the grant of which was previously reported by the Reporting Person on Table II of a Form 4.
(2)	In connection with the Reporting Person's retirement from the Board of the Company on October 25, 2017, the Board determined to accelerate the remaining 190,625 unvested shares of restricted stock units ("RSUs") initially granted to the Reporting Person on February 26, 2016, the grant of which was previously reported by the Reporting Person on Table II of a Form 4.
(3)	Each RSU represents a contingent right to receive 1 share of the Issuer's Class B common stock upon settlement for no consideration.

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