9. Income Taxes

Our provision for income taxes is based on estimated effective tax rates derived from an estimate of annual consolidated earnings before taxes, adjusted for nondeductible expenses, other permanent items and any applicable credits.

The following table presents the provision for income taxes (in thousands) and the effective tax rates:



	Three Months Ended				Six Months Ended
	September 24,		September 26,		September 24,		September 26,
	2016		2015		2016		2015
Income before income taxes	$	102,673	$	42,983	$	124,342	$	92,481
Provision for income taxes	$	24,608	$	8,103	$	30,413	$	24,247
Effective tax rate		24.0%		18.9%		24.5%		26.2%

Our income tax expense for the second quarter and first six months of fiscal year 2017 was below the federal statutory rate primarily due to income in certain foreign jurisdictions taxed below the federal statutory rate and the U.S. R&D tax credit, partially offset by an increase in unrecognized tax benefits. Our income tax expense for the second quarter and first six months of fiscal year 2016 was below the federal statutory rate primarily due to a one-time tax benefit associated with deferred taxes related to U.S. R&D tax credit carryforwards, along with income in certain foreign jurisdictions taxed below the federal statutory rate.

The Company records unrecognized tax benefits for the estimated risk associated with tax positions taken on tax returns. At September 24, 2016, the Company had unrecognized tax benefits of $22.1 million, all of which would impact the effective tax rate if recognized. The Company’s total unrecognized tax benefits are classified as either “Other long-term liabilities” in the consolidated condensed balance sheets or as a reduction to deferred tax assets to the extent that the unrecognized tax benefit relates to deferred tax assets.

The Company recognizes interest and penalties related to unrecognized tax benefits in the provision for income taxes. The Company recognized an immaterial amount of interest in the provision for income taxes during the first six months of fiscal year 2017. As of September 24, 2016, the balance of accrued interest and penalties, net of tax was immaterial. No interest or penalties were recognized during the first six months of fiscal year 2016.

The Company believes it is reasonably possible that the gross unrecognized tax benefits could decrease by approximately $2.3 million in the next 12 months due to the lapse of the statute of limitations applicable to a tax deduction claimed on a prior year tax return.

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 2013 through 2016 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 2013 may be adjusted upon examination by the tax authorities if they have been, or will be, used in a future period. The Company is not currently under an income tax audit in any major taxing jurisdiction.