11. Income Taxes:

The components of the income tax provision are as follows (in thousands):


	December 31,
	2011		2010		2009
Federal:
Current	$	113,290	$	73,756	$	93,590
Deferred		7,486		22,814		6,391

		120,776		96,570		99,981

State:
Current		13,895		10,330		11,315
Deferred		577		1,561		600

		14,472		11,891		11,915

Total	$	135,248	$	108,461	$	111,896

The Company files its tax return on a consolidated basis with its subsidiaries. The remaining affiliated professional contractors file tax returns on an individual basis.

The effective tax rate was 38.29%, 34.86% and 38.89% for the years ended December 31, 2011, 2010 and 2009, respectively. The net decrease in the Company's effective income tax rate for the year ended December 31, 2010 was primarily related to the $10.9 million reduction in its income tax provision resulting from a resolution of certain matters that were under review with taxing authorities.

The differences between the effective rate and the United States federal income tax statutory rate are as follows:


	December 31,
	2011			2010			2009
Tax at statutory rate		35.00	%		35.00	%		35.00	%
State income tax, net of federal benefit		2.66			2.42			2.69
Non-deductible expenses		0.32			0.35			0.40
Change in accrual estimates relating to uncertain tax positions		0.44			(2.81	)		0.82
Other, net		(0.13	)		(0.10	)		(0.02	)

Income tax provision		38.29	%		34.86	%		38.89	%

The significant components of deferred income tax assets and liabilities are as follows (in thousands):


	December 31, 2011									December 31, 2010
	Total			Current			Non- Current			Total			Current			Non- Current
Allowance for uncollectible accounts	$	47,459		$	47,459		$	—		$	34,254		$	34,254		$	—
Net operating loss carryforward		3,533			3,533			—			7,799			7,799			—
Reserves and accruals		40,807			36,828			3,979			37,045			33,378			3,667
Other		483			483			—			488			488			—
Stock-based compensation		18,657			10,586			8,071			18,316			8,700			9,616

Total deferred tax assets		110,939			98,889			12,050			97,902			84,619			13,283

Accrual to cash adjustment		(28,575	)		(28,575	)		—			(24,040	)		(24,040	)		—
Property and equipment		(128	)		—			(128	)		(965	)		—			(965	)
Amortization		(105,753	)		—			(105,753	)		(86,384	)		—			(86,384	)

Total deferred tax liabilities		(134,456	)		(28,575	)		(105,881	)		(111,389	)		(24,040	)		(87,349	)

Net deferred tax (liability) asset	$	(23,517	)	$	70,314		$	(93,831	)	$	(13,487	)	$	60,579		$	(74,066	)

The income tax benefit related to the exercise of stock options, the purchase of shares under the Company's non-qualified employee stock purchase plan and the vesting of restricted stock in excess of amounts recorded as equity compensation expense reduces taxes currently payable and is credited to additional paid-in capital. Such amounts totaled approximately $7.1 million, $3.0 million, and $6.9 million for the years ended December 31, 2011, 2010 and 2009, respectively.

The Company has net operating loss carryforwards for federal and state tax purposes totaling approximately $9.4 million, $20.7 million, and $8.0 million at December 31, 2011, 2010 and 2009, respectively, expiring at various times commencing in 2014. The decrease in net operating loss carryforwards of $11.3 million in 2011 and the increase of $12.7 million in 2010 are primarily due to timing differences related to the recognition of income for tax purposes associated with physician practice acquisitions.

As of December 31, 2011, 2010 and 2009, the Company's liability for uncertain tax positions, excluding accrued interest and penalties, was $16.2 million, $22.3 million and $49.4 million, respectively. The Company had approximately $13.2 million of uncertain tax positions that, if recognized, would favorably impact its effective tax rate at December 31, 2011.

The following table summarizes the activity related to the Company's liability for uncertain tax positions for the years ended December 31, 2011, 2010 and 2009 (in thousands):


	Years Ended December 31,
	2011			2010			2009
Balance at beginning of year	$	22,290		$	49,416		$	47,562
Increases related to prior year tax positions		44			948			—
Decreases related to prior year tax positions		—			(9,569	)		(1,051	)
Increases related to current year tax positions		2,541			2,334			5,867
Decreases related to current year tax positions		(7,203	)		(19,035	)		—
Settlements		13			(500	)		(2,191	)
Decreases related to lapse of statutes of limitations		(1,520	)		(1,304	)		(771	)

Balance at end of year	$	16,165		$	22,290		$	49,416

During the year ended December 31, 2011, the Company decreased its liability for uncertain tax positions by a total of $6.1 million, which is primarily related to reclassifications of certain temporary differences to deferred taxes payable. During the year ended December 31, 2010, the Company decreased its liability for uncertain tax positions by a total of $27.1 million, of which $19.0 million related to reclassifications of certain temporary differences to deferred taxes payable and $9.6 million related to the resolution of certain matters with taxing authorities.

The Company includes interest and penalties related to income tax liabilities in income tax expense. The Company recognized $0.4 million, $1.7 million and $2.5 million, respectively, of interest and penalties related to income tax liabilities during the years ended December 31, 2011, 2010 and 2009. At December 31, 2011 and 2010, the Company's accrued liability for interest and penalties related to income tax liabilities totaled $8.7 million and $8.3 million, respectively.

At December 31, 2011, accounts payable and accrued expenses and other liabilities as presented in the Company's Consolidated Balance Sheet include $3.2 million and $21.7 million, respectively, related to the Company's total liability for uncertain tax positions of $24.9 million. At December 31, 2010, accounts payable and accrued expenses and other liabilities as presented in the Company's Consolidated Balance Sheet include $10.9 million and $19.7 million, respectively, related to the Company's total liability for uncertain tax positions of $30.6 million.

The Company's liability for uncertain tax positions could be reduced over the next 12 months by approximately $3.5 million, excluding accrued interest, due to changes in temporary differences and the expiration of statutes of limitation. Additionally, the Company anticipates that its liability for uncertain tax positions will be increased over the next 12 months by additional taxes of approximately $1.0 million.

The Company is currently subject to U.S. Federal and various state income tax examinations for the tax years 2004 through 2010.