If you change the cost basis of any existing asset in TurboTax on which depreciation was started before the 2022 tax year, it will alter the depreciation history, current year's depreciation will be wrong and all future depreciation will be wrong. You can't do this with TurboTax unless you do an over ride. Note that an over ride is not possible with the online version of the program. Two things happen when you do an over ride.
1) You completely void the TurboTax 100% Accuracy Guarantee
2) You can not e-file the tax return. You have to print, sign and mail it to the IRS (same for state tax return if applicable)
Also keep in mind that the 3115 is a "request" for a change in accounting method. The IRS does not have to approve it. For your situation, unless there's something you're not making the reader aware of, I would not expect the IRS to approve it.
