Rental Property Depreciation Cost Basis

[bjf540]

I have a question I have not been able to find a clear answer to, I purchased a rental property in 2019 that had a tax valuation of 278,900 for land and improvements.  It was calculated as 149,900 for improvements and 129000 for land.  I filed my taxes last year and calculated the cost basis as 53.75% of my total purchase cost for depreciation.   Fast Forward to 2021 and after a town wide reevaluation, my property is assessed at 396,000 with 265,600 for improvements and 130,400 for land.  If i figure out my cost basis based on the new numbers my cost basis would be 67.07% of my total purchase cost.  This would essentially give my a larger amount of depreciation over 27.5 years and reduce my tax liability.   Being that I already filed based on the 53.75% last year, is there anything that can be done to adjust this?  

[MinhT1]

The cost basis of improvements which serves as the basis for depreciation is calculated on the year you started to rent the property and should remain the same over the years unless you add improvements to it. It should not be changed every year with the relative weights of improvements and land of your property.

[Carl]

Your cost basis on a rental asset is determined in the first year the asset is placed in service as a rental asset. It will never change under any circumstances for so long as the asset remains in service as a rental business asset. Not ever.

[AmeliesUncle]

If you think the values you entered in 2019 were wrong, yes you can amend 2019 and correct things on your 2020 tax return.

If you think they were accurate at that time then as was mentioned, you keep using the same numbers.