If you have excess Roth contributions for 2018 and 2019, then you will owe a 6% penalty on every tax return from 2018 through 2023. It is far too late to use the normal removal process or to re-characterize them as traditional IRA contributions. You will need to file amended tax returns for all those years, or at least file amended form 5329s for each year to report and pay the penalties. The IRS will likely come back with a bill for interest on the late payments backdated to the original due date of each tax return; the interest can’t be waived or abated. If you withdraw the excess contributions in 2024, that will be reported on your 2024 return.
The failure to report the re-characterization of the 2020 contributions is a separate issue, that will be dealt with on the 2020 amended tax return along with the 6% penalty for the excess contributions that are carried over from 2018 and 2019. However, if you have not made any further nondeductible contributions to a traditional IRA, then you won’t have additional forms 8606 in future years to worry aboy. You will keep the amended form 8606 from 2020 with your other tax papers to document the taxable basis in your IRA when you begin making withdrawals.
turboTax is no longer available for 2018 or 2019. If you want to do this yourself, you will have to prepare the amended form 5329s by hand. Be sure to download the correct form for each year. At this point, you may want to pay for the assistance of a tax professional, since you have several years of issues to straighten out.
@dmertz further comments?
