Sec Form 4 Filing - de Vries Glen Michael @ Medidata Solutions, Inc. - 2014-02-10

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 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 de Vries Glen Michael 2. Issuer Name and Ticker or Trading Symbol Medidata Solutions, Inc. [ MDSO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) President (Last) (First) (Middle) C/O MEDIDATA SOLUTIONS, INC., 350 HUDSON STREET, 9TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 02/10/2014 (Street) NEW YORK, NY10014 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 02/10/2014 A( 1 ) 18,688 A $ 0 991,354 D Common Stock 02/10/2014 A( 2 ) 123,744 A $ 0 1,115,098 D Common Stock 02/10/2014 M( 3 ) 61,872 A $ 0 1,176,970 D Common Stock 02/11/2014 S 20,000 ( 4 ) D $ 54.3951 ( 5 ) 1,156,970 D

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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) (Ins tr. 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 02/10/2014 A( 6 ) 18,691 ( 6 ) ( 6 ) Common Stock 18,691 ( 6 ) $ 0 18,691 D Restricted Stock Units (Performance-Related) $ 0 02/10/2014 M( 7 ) 30,936 ( 7 ) ( 7 ) Common Stock 30,936 ( 7 ) $ 0 0 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other de Vries Glen Michael C/O MEDIDATA SOLUTIONS, INC. 350 HUDSON STREET, 9TH FLOOR NEW YORK, NY10014 X President Signatures /s/ Michael I. Otner, Attorney-in-Fact 02/12/2014 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Award of shares of restricted stock under the issuer's Second Amended & Restated 2009 Long-Term Incentive Plan (the "2009 LTIP") on February 10, 2014. The restrictions will lapse with respect to one-fourth of the shares on each of February 10, 2015, February 10, 2016, February 10, 2017 and February 10, 2018. ( 2 )Represents restricted stock units earned in connection with a performance-based restricted stock unit ("PBRSU") award on February 14, 2013, based on achievement of certain targets in fiscal year 2013. 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. Shares will be issued in settlement of these restricted stock units in equal annual installments on February 14, 2014, February 14, 2015 and February 14, 2016. ( 3 )Represents restricted stock units earned in connection with a PBRSU award on February 14, 2013, based on achievement of target total stockholder return ("TSR") for 2013 relative to the TSR of companies in the NASDAQ Composite Index for 2013. The restricted stock units were settled at 200% of the target grant amount (the target amount was previously reported in Table II-see footnote 7 below). 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 equal annual installments on February 14, 2014, February 14, 2015 and February 14, 2016. ( 4 )This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 12, 2013. ( 5 )Such transaction was executed in multiple trades at prices ranging from $53.35 to $55.12. The price reported reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. ( 6 )Award of PBRSUs under the 2009 LTIP on February 10, 2014. The number of PBRSUs reported represents a target grant amount. Each PBRSU represents a contingent right to receive 0-200% of that target number of shares of the issuer's common stock, based on the issuer's TSR as compared to the TSR of companies in the NASDAQ Composite Index for the year ending December 31, 2014. The actual number of shares that will be issued, if at all, in settlement of the PBRSUs may range from 0% to 200% of the target grant and will vest in equal annual installments on February 10, 2015, February 10, 2016 and February 10, 2017. The reporting person also received additional awarded PBRSUs, all subject to corporate financial performance metrics. ( 7 )Indicates conversion upon vesting of certain PBRSUs granted on February 14, 2013. The number of shares has been adjusted to reflect the issuer's two-for-one stock split, which became effective on December 16, 2013.

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