Deductions & credits

If you used TurboTax last year, the total AMT depreciation taken on the property appears on the Alternative Minimum Tax Depreciation Report that is included with your complete tax return. The amount to enter is the total of current and prior depreciation shown on this worksheet. You need only the report from last year, as the prior depreciation number is cumulative over the life of the rental asset. See screenshot below.

Most other tax services provide a similar report. If you didn't use TurboTax, you may need to request this report from the service you used last year.