- Statement of Changes in Beneficial Ownership (4)

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	OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5
	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(f) of the Investment Company Act of 1940

1. Name and Address of Reporting Person ^* MOONEY EDWARD J	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 (MM/DD/YYYY) 3/2/2012
(Street) AURORA, IL 60504 (City) (State) (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _ X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. 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)
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	3/2/2012		J		676 ⁽¹⁾ ⁽²⁾	A	$ 0	20258	D
Common Stock	3/2/2012		J		901 ⁽²⁾ ⁽³⁾	A	$ 0	21159	D
Common Stock	3/6/2012		A		2000 ⁽⁴⁾	A	$ 0	23159	D
Common Stock								300	I	Grandchild

*Table II - Derivative Securities Beneficially Owned ( e.g.* , puts, calls, warrants, options, convertible securities)**
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. 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		7. Title and Amount of Securities Underlying Derivative Security (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)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)			11. Nature of Indirect Beneficial Ownership (Instr. 4)
Phantom Stock	$ 0	3/2/2012		J		3047.0286		3/8/2005	3/8/2005 ⁽⁵⁾ ⁽⁶⁾	Common Stock	3047.0286 ⁽⁷⁾	$ 0	9807.9872	D
Stock Options (Right to Buy)	$33.89	3/6/2012		A		6000		3/6/2013 ⁽⁹⁾	3/6/2022	Common Stock	6000	$ 0	6000	D
Stock Options (Right to Buy)	$22.39 ⁽¹⁵⁾ ⁽¹⁶⁾							3/6/2008 ⁽¹⁰⁾	3/6/2017	Common Stock	8704 ⁽⁸⁾ ⁽¹⁶⁾		8704	D
Stock Options (Right to Buy)	$22.6 ⁽¹⁵⁾ ⁽¹⁷⁾							3/4/2009 ⁽¹¹⁾	3/4/2018	Common Stock	8704 ⁽⁸⁾ ⁽¹⁷⁾		8704	D
Stock Options (Right to Buy)	$13.11 ⁽¹⁵⁾ ⁽¹⁸⁾							3/3/2010 ⁽¹²⁾	3/3/2019	Common Stock	8704 ⁽⁸⁾ ⁽¹⁸⁾		8704	D
Stock Options (Right to Buy)	$24.97 ⁽¹⁵⁾ ⁽¹⁹⁾							3/2/2011 ⁽¹³⁾	3/2/2020	Common Stock	8704 ⁽⁸⁾ ⁽¹⁹⁾		8704	D
Stock Options (Right to Buy)	$33.9 ⁽¹⁵⁾ ⁽²⁰⁾							3/8/2012 ⁽¹⁴⁾	3/8/2021	Common Stock	8704 ⁽⁸⁾ ⁽²⁰⁾		8704	D

Explanation of Responses:
( 1)	This restricted stock unit ("RSU") award pursuant to the Second Amendd 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 3,047.0286 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 the phantom stock units was increased proportionately to preserve their value as a result of the Dividend. The number of shares of common stock underlying the phantom 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, 2012, the day the ex-dividend date. The mandatory adjustment in connection with the Dividend was exempt from Section 16(b).
( 8)	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).
( 9)	Directors' Annual (2012) Non-Qualified Stock Option Award: 100% will vest on 3/6/2013.
( 10)	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
( 11)	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.
( 12)	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.
( 13)	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.
( 14)	Directors' Annual (2011) Non-Qalified Stock Option Award: 100% will vest on 3/8/2012.
( 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)	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.
( 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 $32.78.
( 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 $19.01.
( 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 $36.22.
( 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 $49.17.

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
MOONEY EDWARD J C/O CABOT MICROELECTRONICS CORPORATION 870 COMMONS DRIVE AURORA, IL 60504	X

Signatures
/s/ H. Carol Bernstein (Power of Attorney)		3/8/2012
^** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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