I need to amend several years' worth of Forms 8606, Nondeductible IRAs, to correct the Line 2 basis which wasn't being carried forward from previous years. No distributions have ever been taken, so they report only the nondeductible contributions for that year. Up through 2018, the Form 8606 had a checkbox in the header to indicate that it's an amended return. Every year since (2019-2022) does not have this checkbox.
1) What is the proper way to indicate these are amended Forms 8606--should I just write "AMENDED" in the top margin?
2) And should it be accompanied by a cover letter to the IRS with a detailed explanation as to what is being amended, along with documentation?
3) And finally, what would the IRS want to see in terms of documentation? The brokerage's Form 5498 shows the IRA contributions, but how do you prove there were no distributions taken that year? Thanks!
