Roth conversion basis issue - can I file a form 8606 for 2022now and how do I do it?
I have an IRA that was a rollover from an old employer account. I added nondeductibe contributions to it in 2021, 2022, and 2023 (500$ per month).
In late 2023, I did a Roth conversion and moved about half the balance to a Roth. I filed a form 8606 in 2021 so the basis is correct for that year, but I missed inputting it in 2022, and so the basis is not correct for the 2023 conversion in turbotax.
QUESTION do I need to file the 2022 form 8606 now and how do I do that? Do I do that before I file my return? I see there is a place to put an explanation as to why the basis differs from the prior return - can I just put it there?