Income Taxes

Income before income taxes consisted of (in thousands):



	Fiscal Years Ended
	March 31, 2018		March 25, 2017		March 26, 2016
U.S.	$	91,220	$	137,654	$	108,133
Non-U.S.	173,879		177,393		67,856
	$	265,099	$	315,047	$	175,989

The provision (benefit) for income taxes consists of (in thousands):



	Fiscal Years Ended
	March 31, 2018			March 25, 2017		March 26, 2016
Current:
U.S.	$	66,082		$	28,940	$	28,313
Non-U.S.	21,812			7,234		703
Total current tax provision	$	87,894		$	36,174	$	29,016
Deferred:
U.S.	19,309			2,576		18,242
Non-U.S.	(4,099		)	15,088		5,101
Total deferred tax provision	15,210			17,664		23,343
Total tax provision	$	103,104		$	53,838	$	52,359

The effective income tax rates differ from the rates computed by applying the statutory federal rate to pretax income as follows (in percentages):



	Fiscal Years Ended
	March 31, 2018		March 25, 2017		March 26, 2016
U.S. federal statutory rate	31.6		35.0		35.0
Foreign income taxed at different rates	(8.9	)	(8.6	)	(0.6	)
Transition tax on deferred foreign income	20.3		—		—
Remeasurement of U.S. deferred tax balance	2.3		—		—
Research and development tax credits	(2.5	)	(1.8	)	(5.6	)
Stock based compensation	(4.5	)	(7.3	)	—
Other	0.6		(0.2	)	1.0
Effective tax rate	38.9		17.1		29.8

The Tax Cuts and Jobs Act (the "Tax Act") was enacted on December 22, 2017. The Tax Act reduces the US federal corporate tax rate from 35% to 21% as of January 1, 2018, resulting in a blended U.S. federal statutory rate of 31.6% for fiscal year 2018. The Tax Act restricts the deductibility of certain business expenses, requires companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax-deferred and creates new taxes on certain foreign sourced earnings, among other provisions. As of March 31, 2018, we have not completed our accounting for the income tax effects of the Tax Act. We have made a reasonable estimate of the one-time transition tax liability and the remeasurement of our existing deferred tax balances. We recognized a provisional amount of $60.1 million which is included as a discrete component of income tax expense. We will continue to refine our calculations as additional analysis is completed. Our estimates may also be affected as we gain a more thorough understanding of the tax law.

Provisional Amounts

We remeasured certain deferred tax assets and liabilities based on the rate at which they are expected to reverse in the future, which is generally 21%. The provisional amount recorded as a discrete component of income tax expense related to the remeasurement of our deferred tax balances was $6.1 million of tax expense. We are still analyzing certain aspects of the Tax Act and refining our calculations, which could potentially affect the measurement of these balances or give rise to new deferred tax amounts.

We recorded a provisional amount of $53.9 million for the one-time transition tax liability as a discrete component of income tax expense. The one-time transition tax is based on our total post-1986 earnings and profits ("E&P") that were previously deferred from U.S. income taxes, and is based in part on the amount of those earnings held in cash and other specified assets. The amount may change when we finalize the calculation of E&P and finalize the amounts held in cash or other specified assets on the applicable measurement date.

As of March 31, 2018, unremitted earnings from our foreign subsidiaries that have been included in our computation of the transition tax are not expected to be indefinitely reinvested. No taxes have been accrued for foreign withholding and distribution taxes on these earnings as these amounts are not material. We have not provided additional income taxes for any other outside basis differences inherent in these entities, as these amounts continue to be indefinitely reinvested in foreign operations. Determining the amount of unrecognized deferred tax liability related to any other outside basis differences in these entities is not practicable at this time.

Significant components of our deferred tax assets and liabilities as of March 31, 2018 and March 25, 2017 are (in thousands):



	March 31, 2018			March 25, 2017
Deferred tax assets:
Accrued expenses and allowances	$	5,793		$	9,002
Net operating loss carryforwards	3,646			6,294
Research and development tax credit carryforwards	12,701			13,977
Stock based compensation	14,156			17,356
Other	2,402			9,141
Total deferred tax assets	$	38,698		$	55,770
Valuation allowance for deferred tax assets	(14,671		)	(12,570		)
Net deferred tax assets	$	24,027		$	43,200
Deferred tax liabilities:
Depreciation and amortization	$	9,184		$	13,837
Acquisition intangibles	13,427			16,301
Total deferred tax liabilities	$	22,611		$	30,138
Total net deferred tax assets	$	1,416		$	13,062

Deferred tax assets and liabilities are recorded for the estimated tax impact of temporary differences between the tax basis and book basis of assets and liabilities. A valuation allowance is established against a deferred tax asset when it is more likely than not that the deferred tax asset will not be realized. The valuation allowance increased by $2.1 million in fiscal year 2018 with no material impact to income tax expense. The Company continued to record a valuation allowance on various state net operating losses and tax credits due to the likelihood that they will expire or go unutilized because the Company does not expect to recognize sufficient income in the jurisdictions in which the tax attributes were created. Management believes that the Company’s results from future operations will generate sufficient taxable income in the appropriate jurisdictions and of the appropriate character such that it is more likely than not that the remaining deferred tax assets will be realized.

At March 31, 2018, the Company had gross federal net operating loss carryforwards of $9.7 million, all of which related to acquired companies and are, therefore, subject to certain limitations under Section 382 of the Internal Revenue Code. The federal net operating loss carryforwards expire in fiscal years 2019 through 2031.

At March 31, 2018, the Company had gross state net operating loss carryforwards of $35.8 million. The state net operating loss carryforwards expire in fiscal years 2019 through 2034. In addition, the Company had $12.7 million of state research and development tax credit carryforwards. Certain of these state tax credits will expire in fiscal years 2021 through 2033. The remaining state tax credit carryforwards do not expire.

The following table summarizes the changes in the unrecognized tax benefits (in thousands):



	March 31, 2018			March 25, 2017
Beginning balance	$	30,858		$	18,796
Additions based on tax positions related to the current year	26,602			12,127
Reductions based on tax positions related to the prior years	(2,296		)	(65		)
Ending balance	$	55,164		$	30,858

The Company records unrecognized tax benefits for the estimated risk associated with tax positions taken on tax returns. At March 31, 2018, the Company had gross unrecognized tax benefits of $55.2 million, all of which would impact the effective tax rate if recognized. During fiscal year 2018, the Company had gross increases of $26.6 million related to current year unrecognized tax benefits, as well as gross decreases of $2.3 million. The Company’s unrecognized tax benefits are classified as “Non-current income taxes” in the Consolidated Balance Sheet.

The Company recognizes interest and penalties related to unrecognized tax benefits in the provision for income taxes. During fiscal years 2018 and 2017 we recognized interest expense, net of tax, of approximately $0.8 million and $0.2 million, respectively.

The Company and its subsidiaries are subject to U.S. federal income tax as well as income tax in multiple state and foreign jurisdictions. Fiscal years 2015 through 2018 remain open to examination by the major taxing jurisdictions to which the Company is subject, although carry forward attributes that were generated in tax years prior to fiscal year 2015 may be adjusted upon examination by the tax authorities if they have been, or will be, used in a future period. The Company's United Kingdom subsidiaries are currently under a limited scope tax audit for certain income tax matters related to fiscal year 2016. The Company believes it has accrued adequate reserves related to the matters under examination. The Company is not under an income tax audit in any other major taxing jurisdiction.