The Treasury/JCT Method estimates the tax expenditure as the sum of the tax saving from deductions to qualified retirement saving plans, the savers’ credit, and the exemption of current income accrued within qualified plans minus the additional taxes if all withdrawals from qualified plans were taxable, accounting for all interactions among these provisions. Baseline is the law in place as of December 18, 2019, with the Tax Cuts and Jobs Act of 2017 (TCJA) permanently extended.