A taxpayer who failed to claim the depreciation deduction for the las 12 years may cor4rect this by
1) Filing amended returns for all open years when the incorrect amount was claimed.
2) Filing Form 3115. Application to 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) Increasing the basis of the property by the amount of depreciation that could have been claimed.