Prior Year Depreciation Error

[wleighton]

I have one rental property where it appears I made a mistake the past two years by using the wrong cost basis for depreciation. 

Is the cost basis simply the purchase price minus the cost of land? Or should it be calculated as the cost of improvements (excluding land)/total assessed value x the purchase price? I seem to have been misguided at one point. 

My question now is, should I enter the prior year depreciation total, since my total accumulated depreciation amount does not match IRS tables (what it should be, based on the correct cost basis)? When I do enter prior years' depreciation, it does seem to adjust this year's depreciation a bit lower. Will this correct my prior years' mistake over time? Or do I need to file amended returns to correct my error?

[ColeenD3]

If your basis for depreciation is incorrect, you need to amend. When converting property from personal to rental, your basis is the lower of the adjusted basis or Fair Market Value on the date of conversion. Adjusted basis includes any improvements made prior to the conversion. If it was always rental, you would include improvements in the basis.