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 *
WILKINSON STEVEN V
  2. Issuer Name and Ticker or Trading Symbol
CABOT MICROELECTRONICS CORP [CCMP]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O CABOT MICROELECTRONICS CORPORATION, 870 COMMONS DRIVE
3. Date of Earliest Transaction (Month/Day/Year)
03/02/2012
(Street)

AURORA, IL 60504
4. If Amendment, Date Original Filed(Month/Day/Year)
03/08/2012
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 03/02/2012   J   676 (1) (2) A $ 0 31,138 D  
Common Stock 03/02/2012   J   901 (2) (3) A $ 0 32,039 D  
Common Stock 03/06/2012   A   2,000 (4) A $ 0 34,039 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
Phantom Stock $ 0 03/02/2012   J   5,170.1181   06/17/2003(6) 06/17/2003(5)(6) Common Stock 5,170.1181 (7) $ 0 16,641.9344 D  
Stock Options (Right to Buy) $ 33.89 03/06/2012   A   6,000   03/06/2013(8) 03/06/2022 Common Stock 6,000 $ 0 6,000 D  
Stock Options (Right to Buy) $ 22.39 (15) (17)             03/06/2008(9) 03/06/2017 Common Stock 8,704 (16) (17)   8,704 D  
Stock Options (Right to Buy) $ 22.6 (15) (18)             03/04/2009(10) 03/04/2018 Common Stock 8,704 (16) (18)   8,704 D  
Stock Options (Right to Buy) $ 13.11 (15) (19)             03/03/2010(11) 03/03/2019 Common Stock 8,704 (16) (19)   8,704 D  
Stock Options (Right to Buy) $ 24.97 (15) (20)             03/02/2011(12) 03/02/2020 Common Stock 8,704 (16) (20)   8,704 D  
Stock Options (Right to Buy) $ 33.9 (15) (21)             03/08/2012(13) 03/08/2021 Common Stock 8,704 (16) (21)   8,704 D  
Stock Options (Right to Buy) $ 45.31 (15) (22)             03/12/2003(14) 03/12/2012 Common Stock 10,880 (16) (22)   10,880 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
WILKINSON STEVEN V
C/O CABOT MICROELECTRONICS CORPORATION
870 COMMONS DRIVE
AURORA, IL 60504
  X      

Signatures

 /s/ H. Carol Bernstein (Power of Attorney)   03/08/2012
**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) This restricted stock unit ("RSU") award pursuant to the Second Amended and Restated 2000 Equity Incentive Plan ("EIP") was previously reported by the reporting person as a RSU convertible into 2,000 shares of common stock.
(2) As required by Section 8.6 of the EIP and approved by the Compensation Committee of the Board of Directors of the Company, the unvested portion of the RSU award was proportionally adjusted on March 2, 2012 to preserve its value in connection with a leveraged recapitalization of the Company via a special cash dividend (the "Dividend") of $15.00 per share declared on February 13, 2012 with a record date of February 23, 2012, a payable date date of March 1, 2012 and an ex-dividend date of March 2, 2012. The number of shares of common stock underlying the unvested portion of the RSU award was increased proportionately to preserve its value as a result of the Dividend. The number of shares of common stock underlying the unvested portion of the RSU award was increased by a factor of 1.45068 rounded down to the nearest whole unit, which is a ratio of the Official Nasdaq Closing Price of $51.92 on March 1, 2012, the day immediately before the ex-dividend date, to the Official Nasdaq Opening Price of $35.79 on March 2, 2012, the day the ex-dividend date. The mandatory adjustments in connection with the Dividend were exempt from Section 16(b).
(3) This "RSU" award pursuant to the EIP was previously reported by the reporting person as a RSU convertible into 2,000 shares of common stock.
(4) Directors' Annual (2012) Restricted Stock Unit Award pursuant to 2012 Omnibus Incentive Plan ("OIP"). 100% will vest on 3/6/2013.
(5) Rights to acquire shares pursuant to Directors' Deferred Compensation Plan are already earned.
(6) Rights to aquire shares pursuant to Directors' Deferred Compensation Plan are already earned.
(7) The reporting person previously reported phantom stock units convertible into a total of 11,471.8161 shares of common stock earned pursuant to the Directors' Deferred Compensation Plan ("DDCP"). As required by Section 4(d) of the DDCP and approved by the Nominating and Corporate Governance Committee of the board of Directors of the Company, the phantom stock units earned were adjusted on March 2, 2012 in connection with the Dividend. The number of shares of common stock underlying thephantom stock units was increased proportionately to preserve their value as a result of the Dividend. The numbers of shares of common stock underlying thephantom stock units was increased by a factor of 1.45068 rounded down to the nearest whole option, which is a ratio of the Official Nasdaq Closing Price of $51.92 on March 1, 2012, the day immediately before the ex-dividend date, to the official Nasdaq Opening Price of $35.79 on March 2, 1012, the ex-dividend date. The mandatory adjustment in connection with the Dividend was exempt from Section 16(b).
(8) Directors' Annual (2012) Non-Qualified Stock Option Grant pursuant to 2012 Omnibus Incentive Plan ("OIP"). 100% will vest on 3/6/2013.
(9) Directors' Annual (2007) Non-Qualified Stock Option Award Vesting Schedule: 25% 3/6/08, 25% 3/6/09, 25% 3/6/10, 25% 3/6/11
(10) Directors' Annual (2008) Non-Qualified Stock Option Award Vesting Schedule: 25% 3/4/2009, 25% 3/4/2010, 25% 3/4/2011, 25% 3/4/2012.
(11) Directors' Annual (2009) Non-Qualified Stock Option Award Vesting Schedule: 25% 3/3/2010; 25% 3/3/2011; 25% 3/3/2012; 25% 3/3/2013.
(12) Directors' Annual (2010) Non-Qualified Stock Option Award Vesting Schedule: 25% 3/2/2011; 25% 3/2/2012; 25% 3/2/2013; 25% 3/2/2014.
(13) Directors' Annual (2011) Non-Qualified Stock Option Award: 100% will vest on 3/8/2012.
(14) Pursuant to Second Amended and Restated Equity Incentive Plan (EIP) and Compensation Committee action 9/27/04, grant agreement amended to provide that Vesting Schedule is: 25% on 3/12/03 25% on 3/12/04 25% on 3/12/05 25% on 9/1/05
(15) Required by Section 8.6 of the EIP and approved by the Compensation Committee of the Board of Directors of the Company, the exercise price of the option was proportionally adjusted on March 2, 2012 to preserve its value as a result of the leveraged recapitalization via the Dividend. The exercise price of each outstanding stock option was decreased by a factor of 0.68933 rounded up to the nearest whole cent, which is a ratio of the Official Nasdaq Opening Price of $35.79 on March 2, 2012, the ex-dividend date, to the Official Nasdaq Closing Price of $51.92 on March 1, 2012, the day immediately before the ex-dividend date. The mandatory adjustments in connection with the Dividend were exempt from Section 16(b).
(16) Also as a result of the leveraged recapitalization via the Dividend, the number of stock options subject to each outstanding award was increased proportionately to preserve its value as a result of the Dividend. The number of stock options was increased by a factor of 1.45068 rounded down to the nearest whole option, which is a ratio of the Official Nasdaq Closing Price of $51.92 on March 1, 2012, the day immediately before the ex-dividend date, to the Official Nasdaq Opening Price of $35.79 on March 2, 2012, the ex-dividend date. The mandatory adjustments in connection with the Dividend were exempt from Section 16(b).
(17) This option pursuant to the EIP, was previously reported by the reporting person as an option for 6,000 shares of common stock at an exercise price of $32.47.
(18) This option pursuant to the EIP, was previously reported by the reporting person as an option for 6,000 shares of common stock at an exercise price of $32.78.
(19) This option pursuant to the EIP, was previously reported by the reporting person as an option for 6,000 shares of common stock at an exercise price of $19.01.
(20) This option pursuant to the EIP, was previously reported by the reporting person as an option for 6,000 shares of common stock at an exercise price of $36.22.
(21) This option pursuant to the EIP, was previously reported by the reporting person as an option for 6,000 shares of common stock at an exercise price of $49.17.
(22) This option pursuant to the EIP, was previously reported by the reporting person as an option for 7,500 shares of common stock at an exercise price of $65.73.

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