14. Income Taxes

We account for income taxes under the asset and liability method. The provision for income taxes recorded in interim periods is based on our estimate of the annual effective tax rate applied to year-to-date income before provision for income taxes, adjusted for discrete items required to be recognized in the period in which they are incurred. In each quarter, we update our estimate of the annual effective tax rate, and if the estimated annual tax rate changes, we make a cumulative adjustment in that quarter. Our quarterly tax provision and our quarterly estimate of the annual effective tax rate can be subject to volatility due to several factors, including our ability to accurately forecast annual income before provision for income taxes in each of the tax jurisdictions in which we operate.

The provision for income taxes of $17.4 million and $56.5 million for the three and six months ended December 2022, respectively, represented estimated federal, foreign, and state income taxes. The effective tax rate for the three and six months ended December 2022 diverged from the combined U.S. federal and state statutory tax rate primarily due to the impact of tax law changes becoming effective in our fiscal 2023, including non-creditable foreign withholding taxes resulting from the final foreign tax credit regulations published in January 2022 and the research and development capitalization rules increasing our global intangible low-taxed income, or GILTI, resulting from the U.S. Tax Cuts and Jobs Act of 2017, and non-deductible officer compensation, partially offset by the benefit of foreign income taxed at lower rates, and research credits.

The provision for income taxes of $2.0 million and $7.9 million for the three and six months ended December 2021, respectively, represented estimated federal, foreign, and state income taxes. The effective tax rate for the three and six months ended December 2021, diverged from the combined U.S. federal and state statutory tax rate, primarily due to foreign income taxed at lower rates, the benefit of research credits and foreign tax credits, partially offset by foreign withholding taxes, non-deductible officer compensation, non-deductible stock-based compensation, and GILTI.

The total liability for gross unrecognized tax benefits related to uncertain tax positions increased $21.4 million during the six months ended December 2022, to $51.2 million, and was included in other long-term liabilities on our condensed consolidated balance sheets. If recognized, the total gross unrecognized tax benefits would reduce the effective tax rate on income from continuing operations. Accrued interest and penalties related to unrecognized tax benefits as of December 2022 were $2.7 million; this balance increased by $0.2 million compared to June 2022. We classify interest and penalties as components of income tax expense. Any prospective adjustments to our unrecognized tax benefits will be recorded as an increase or decrease to income tax expense and cause a corresponding change to our effective tax rate. Accordingly, our effective tax rate could fluctuate materially from period to period.

Our major tax jurisdictions are the United States, Hong Kong SAR, Israel, Japan and the United Kingdom. From fiscal 2016 onward, we remain subject to examination by one or more of these jurisdictions.