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 *
Hirschfeld Steven Isaac
  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)
Vice Chairman
(Last)
(First)
(Middle)
C/O MEDIDATA SOLUTIONS, INC, 350 HUDSON STREET, 9TH FLOOR
3. Date of Earliest Transaction (Month/Day/Year)
02/26/2016
(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 02/26/2016   M   9,520 (1) A $ 0 115,313 D  
Common Stock 02/26/2016   F   4,937 (2) D $ 34.85 110,376 D  
Common Stock 02/26/2016   A(3)   25,491 A $ 0 135,867 D  

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
Hirschfeld Steven Isaac
C/O MEDIDATA SOLUTIONS, INC
350 HUDSON STREET, 9TH FLOOR
NEW YORK, NY 10014
      Vice Chairman  

Signatures

 /s/ Michael I. Otner, Attorney-in-Fact   03/01/2016
**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 13, 2015, based on achievement of certain targets in fiscal year 2015. The restricted stock units were settled at 128.1% of the target grant amount. Each restricted stock unit represents a contingent right to receive one share of the issuer's common stock. Shares will be issued in settlement of these restricted stock units in annual installments on February 26, 2016, February 26, 2017, and February 26, 2018.
(2) Shares withheld by Medidata to satisfy the tax withholding obligation in connection with the vesting of the PBRSU award referenced above.
(3) Award of shares of restricted stock under the issuer's Second Amended & Restated 2009 Long-Term Incentive Plan (the "2009 LTIP") on February 26, 2016. The restrictions will lapse with respect to one-fourth of the shares on each of February 26, 2017, February 26, 2018, February 26, 2019, and February 26, 2020.

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