The sum of all state or local income tax refunds attributable to the prior year return is calculated using these steps:
The sum of all prior year extensions and payments for a state or local authority made during the current tax year is divided by total payments on the current tax year's return.
The result from step 1a is multiplied by the total prior year refund. The result is the amount of tax allocated to the following year.
The result from step 1b is subtracted from the total refund to determine the refund amount attributable to the prior year. The same formula is used for any city refunds or payments the client might have.
The current tax year AMT liability is divided by the current tax year's Federal marginal tax rate (which you can find on the YYYY Diagnostic Worksheet.) The result is the tentative amount of the refund where no tax benefit is derived due to AMT.
The smaller of the tentative amount (from Step 2) or the sum of all refunds attributable to the current tax year (from Step 1b) is used in the following steps to be re-included in the prior year's return.
The current tax year's itemized deductions are recalculated to include the amount from Step 3. (Specifically, Line 1 of the YYYY Itemized Deductions Worksheet is reduced by this amount.)
The current tax year's taxable income is recalculated based on any changes to total itemized deductions calculated in Step 4.
The current tax year's regular tax is recalculated based on the appropriate method (Tax Tables, Qualified Dividends & Capital Gains Tax Worksheet, or Schedule D Tax Worksheet.) Taxes are also recalculated for Form 8615 and Schedule J.
The current tax year's AMT liability is recalculated.
The current tax year's total tax liability is recalculated (Steps 6 and 7 are summed.)