A taxpayer who failed to claim the depreciation for the last 12 years may correct this by:

1) Filing amended returns for all open years when the incorrect amount was claimed.

2) Filing Form 3115, Application for Change in Accounting Method

3) Including the unclaimed depreciation as "Other Depreciation" on line 16 of Form 4562. Depreciation and Amortization, in the current year.

4) Increase the basis of the property by the amount of depreciation that could have been claimed.