4. Income Taxes

Effective tax rates for the thirteen weeks ended March 26, 2020 and March 28, 2019 were based on the Company’s forecasted annualized effective tax rates and were adjusted for discrete items that occurred within each period. The Company’s effective income tax rate was 17.4% for the thirteen weeks ended March 26, 2020 and 16.6% for the thirteen weeks ended March 28, 2019. The effective income tax rate in each of these periods was lower than the statutory federal income tax rate of 21.0% primarily due to the recognition of income tax benefits for discrete items, the largest of which were tax deductions in excess of book expense related to stock option exercises. For the thirteen weeks ended March 26, 2020 and March 28, 2019, benefits for discrete items were partially offset by the recognition of discrete expense totaling $2.2 million and $0.1 million, respectively, for loss contingencies related to uncertain tax positions, including estimated interest and penalties related to such positions.

The Company accounts for income taxes under the liability method in accordance with ASC 740, Income Taxes, which requires the recognition of deferred tax assets and liabilities for the future tax consequences attributable to differences between the financial statement carrying amounts and tax basis of existing assets and liabilities. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Changes in tax laws and rates could affect recorded deferred tax assets and liabilities in the future. The effect on deferred tax assets and liabilities of a change in tax laws or rates is recognized in the period that includes the enactment date of such a change.

The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which the associated temporary differences became deductible. On a quarterly basis, the Company evaluates whether it is more likely than not that its deferred tax assets will be realized in the future and concludes whether or not a valuation allowance must be established.

The Company accounts for uncertain tax positions in accordance with ASC 740. ASC 740-10 clarifies the accounting for uncertainty in income taxes recognized in an enterprise's financial statements using a two-step process for evaluating tax positions taken, or expected to be taken, on a tax return. The Company may only recognize the tax benefit from an uncertain tax position if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such a position should be measured based on the largest benefit that has a greater than 50 percent likelihood of being realized upon ultimate settlement. In addition, the Company recognizes a loss contingency for uncertain tax positions when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. The amounts recognized for uncertain tax positions require that management make estimates and judgments based on provisions of the tax law, which may be subject to change or varying interpretations. The Company includes estimated interest and penalties related to uncertain tax position accruals within accrued expenses and other current liabilities in the condensed consolidated balance sheets and within income tax expense in the condensed consolidated statements of operations and comprehensive income.