8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (date of earliest event reported):

November 2, 2006

Cabot Microelectronics Corporation

(Exact name of registrant as specified in its charter)

Delaware	000-30205	36-4324765
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification)

870 Commons Drive, Aurora, Illinois	60504
(Address of principal executive offices)	(Zip Code)

(630) 375-6631

(Registrant’s telephone number, including area code)

Not applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o   Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o   Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o   Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o   Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 2.02Results of Operations and Financial Condition.

On November 2, 2006, at 10:00 a.m. Central Standard Time (CST), Cabot Microelectronics Corporation (CMC), in connection with its Analyst Day, will make available on the “Investor Relations” section of its website (www.cabotcmp.com) certain historical financial information regarding three non-GAAP (Generally Accepted Accounting Principles) financial measures. These three non-GAAP financial measures are: non-GAAP operating cash flow, which is presented for fiscal years 2000 through 2006; non-GAAP return on invested capital, which is presented for the 12-month period ending June 30, 2006; and non-GAAP cash operating expense, which is provided by quarter for fiscal years 2003 through 2006. William Johnson, CMC’s Chief Financial Officer, will be discussing these financial measures during the portion of the Analyst Day presentation entitled “Financial Review”.

Attached to this Form 8-K, as Exhibit 99.1 “Reconciliation of Non-GAAP Financial Measures”, are tables that reconcile the non-GAAP financial measures to the most directly comparable GAAP financial measures for the periods noted above, as required pursuant to the SEC’s Regulation G.

CMC’s management believes that these non-GAAP financial measures provide meaningful supplemental information regarding its performance and liquidity by, for example, excluding certain non-cash expenses that may not relate closely to core business operating results or calculating cash flow on a simplified basis to show CMC’s cash-generation capabilities. CMC believes that both management and investors may benefit from referring to these non-GAAP financial measures in assessing and understanding CMC’s performance. These non-GAAP financial measures may also facilitate management’s internal comparisons of CMC’s current to historical performance and liquidity, and to analyze performance relative to the performance of a number of companies that operate in similar industries. CMC believes that these non-GAAP financial measures are useful to investors in allowing for greater transparency with respect to supplemental information used by management in its financial and operational decision-making. However, management does not intend for the non-GAAP financial measures to be considered in isolation or as a substitute for results prepared in accordance with GAAP.

This information is being furnished pursuant to Item 2.02 of Form 8-K and shall not be deemed “filed” for purposes of Section 18 of the Securities and Exchange Act of 1934, as amended (the “Exchange Act”), or incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 7.01Regulation FD Disclosure.

On November 2, 2006, at 10:00 a.m. CST, Cabot Microelectronics Corporation will publish a presentation entitled “Cabot Microelectronics Analyst Day Presentation (November 2, 2006)” in the “Presentations” area of the “Investor Relations” section of CMC’s website. This presentation will be discussed during its Analyst Day activities, which will be webcast live on November 2, 2006, from 10:00 a.m. to noon and from 1:30 p.m. to 3:00 p.m., CST. It includes a discussion of certain aspects of CMC’s business and certain non-GAAP financial measures, as described in greater detail in Item 2.02 above.

CMC assumes no obligation to update such information in the future.

This information is being furnished pursuant to Item 7.01 of Form 8-K and shall not be deemed “filed” for purposes of Section 18 of the Securities and Exchange Act of 1934, as amended (the “Exchange Act”), or incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01Financial Statements and Exhibits.

(c)	Exhibits
	The following exhibit is being furnished, not filed, herewith pursuant to Items 2.02 and 7.01 of Form 8-K:
	99.1“Reconciliation of Non-GAAP Financial Measures.”

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	CABOT MICROELECTRONICS CORPORATION
Date: November 2, 2006	By:	/s/ WILLIAM S. JOHNSON
		William S. Johnson
		Vice President and Chief Financial Officer
		[Principal Financial Officer]

INDEX TO EXHIBITS

Exhibit Number	Title
99.1	“Reconciliation of Non-GAAP Financial Measures.”

EX-99.1

Exhibit 99.1Reconciliation of Non-GAAP Financial Measures

The following presents reconciliations of the non-GAAP financial measures included in the “Cabot Microelectronics Analyst Day (November 2, 2006)” presentation.

Reconciliation of non-GAAP return on invested capital (ROIC) to the nearest comparable GAAP measures (in thousands)
				For the twelve months ended June 30, 2006
GAAP Operating Income			$	44,581
Less: Non-GAAP income taxes (35%)				15,603
Non-GAAP after-tax operating income			$	28,978
	As of  June 30, 2005	As of June 30, 2006
GAAP
Short-term capital lease obligation	1,150	1,232
Long-term capital lease obligation	5,679	4,680
Total capital lease obligation*	6,829	5,912
Average capital lease obligation				6,371
Stockholders' equity	334,272	364,884
Average stockholder's equity				349,578
Less:
Total cash, cash equivalents and short-term investments				169,482
Non-GAAP invested capital
(Average debt and stockholders'
equity less cash, cash equivalents
and short-term investments)			$	186,467
Non-GAAP return on invested capital (ROIC)				15.5	%
* Capital lease obligations are treated as debt for purposes of calculating ROIC.
No other debt is outstanding as of June 30, 2005, and June 30, 2006.

Reconciliations of non-GAAP cash operating expense measures to the nearest comparable GAAP measures (in thousands)
	Quarter Ended
		December 31,		March 31,			June 30,		September 30,
		2002		2003			2003		2003
GAAP operating expenses	$	15,666	$	16,843		$	18,294	$	20,499
Less non-cash operating expense items:
Depreciation and amortization		1,961		1,979			2,040		2,178
Non-GAAP cash operating expenses	$	13,705	$	14,864		$	16,254	$	18,321
	Quarter Ended
		December 31,		March 31,			June 30,		September 30,
		2003		2004			2004		2004
GAAP operating expenses	$	19,715	$	21,340		$	21,137	$	20,727
Less non-cash operating expense items:
Depreciation and amortization		2,247		2,426			2,534		2,624
Non-GAAP cash operating expenses	$	17,468	$	18,914		$	18,603	$	18,103
	Quarter Ended
		December 31,		March 31,			June 30,		September 30,
		2004		2005			2005		2005
GAAP operating expenses	$	19,385	$	21,411		$	20,591	$	24,039
Less non-cash operating expense items:
Depreciation and amortization		2,585		2,631			2,542		2,400
Impairment of property, plant and equipment		-		-			-		111
(Gain) loss on disposal of property, plant and equipment		-		-			20		73
Non-GAAP cash operating expenses	$	16,800	$	18,780		$	18,029	$	21,455
	Quarter Ended
		December 31,		March 31,			June 30,		September 30,
		2005		2006			2006		2006
GAAP operating expenses	$	25,099	$	24,640		$	26,651	$	28,234
Less non-cash operating expense items:
Depreciation and amortization		2,651		2,753			2,868		3,157
Share-based compensation		2,344		2,488			2,563		2,621
Purchased in-process research and development		-		-			-		1,120
Impairment of property, plant and equipment		-		-			-		657
(Gain) loss on disposal of property, plant and equipment		54		(30	)		24		60
Non-GAAP cash operating expenses	$	20,050	$	19,429		$	21,196	$	20,619

Reconciliations of non-GAAP operating cash flow measures to the nearest comparable GAAP measures (in thousands)
	Year Ended September 30,
		2000			2001		2002		2003		2004		2005		2006
GAAP net cash provided by operating activities	$	31,870		$	62,544	$	53,500	$	47,584	$	64,210	$	47,962	$	58,668
Less: additions to property, plant and equipment		38,923			35,328		35,259		16,396		10,968		21,137		22,230
Non-GAAP operating cash flow		($7,053	)	$	27,216	$	18,241	$	31,188	$	53,242	$	26,825	$	36,438

In addition, on the same slide of the "Cabot Microelectronics Analyst Day" presentation on which the non-GAAP measures above are presented, certain terms were abbreviated as follows:

Abbreviated Description per Analyst Day Presentation   Equivalent GAAP Description per Statement of Cash Flows:

Non-cash Items        Adjustments to reconcile net income to net cash

Working Capital Change       Changes in operating assets and liabilities