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 * Otner Michael I.   2. Issuer Name and Ticker or Trading Symbol Medidata Solutions, Inc. [MDSO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) EVP-General Counsel (Last) (First) (Middle) C/O MEDIDATA SOLUTIONS, INC.,, 350 HUDSON STREET, 9TH FLOOR 3. Date of Earliest Transaction (Month/Day/Year) 02/12/2019 (Street) NEW YORK, NY 10014 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 Common Stock 02/12/2019   A   25,490 (1) A $ 71.98 83,627 (2) D   Common Stock 02/12/2019   F   10,538 (3) D $ 71.98 73,089 D   Common Stock 02/12/2019   A   12,698 (4) A $ 0 85,787 D   Common Stock 02/13/2019   F   1,648 (5) D $ 72.05 84,139 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 (Performance-Related)

$ 0

02/12/2019

A

12,698

(6)

(6)

Common Stock

(6)

$ 0

12,698

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Otner Michael I. C/O MEDIDATA SOLUTIONS, INC., 350 HUDSON STREET, 9TH FLOOR NEW YORK, NY 10014			EVP-General Counsel

Signatures

/s/ Michael I. Otner		02/14/2019
**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)	Represents restricted stock units earned in connection with a performance-based restricted stock unit ("PBRSU") award on February 26, 2016, based on achievement of certain TSR performance targets for the three years ended December 31, 2018. The restricted stock units were settled at 200% of the target grant amount. Each restricted stock unit represents a contingent right to receive one share of the issuer's common stock.
(2)	Included are 119 shares which were purchased pursuant to the terms of the Medidata Solutions, Inc. Employee Stock Purchase Plan on December 31, 2018.
(3)	Shares withheld by Medidata to satisfy the tax withholding obligation in connection with the vesting of the PBRSU award referenced above.
(4)	Award of shares of restricted stock under the issuer's 2017 Long-Term Incentive Plan (the "2017 LTIP") on February 12, 2019. The restrictions will lapse with respect to one-fourth of the shares on each of February 12, 2020, February 12, 2021, February 12, 2022, and February 12, 2023.
(5)	Shares withheld by Medidata to satisfy the tax withholding obligation in connection with the vesting of previously awarded restricted stock.
(6)	Award of PBRSUs under the 2017 LTIP on February 12, 2019. The number of PBRSUs represents a target amount. Each PBRSU represents a contingent right to receive 0-225% of that target number of shares of the issuer's common stock, (i) 50% based on the issuer's TSR as compared to the TSR of companies in the Russell 2000 Index for the three years ending December 31, 2021, and (ii) 50% based on the Company's revenue attainment for the three years ending December 31, 2021. The shares will vest immediately upon being earned.

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