Thanks for the comprehensive responses. Realized I didn't make it clear if I contributed 2020 - 2022 ... I did contribute the max allowed amount for each of those years. So my cumulative rolling basis should be $30.5K. So looks like I need to file both Form 1040-X and Form 8606 for 2020 - 2022 and Form 1040-X and corrected Form 8606 for 2023.
1. @dmertz, do you know if these can be filed electronically for each year or would I have to mail these in?
2. @fanfare, looking at 1040-X, makes sense leaving 1 - 23 blank as well as Part 1, 24 - 30. In part II, I'm assuming I'll need to explain the missing Form 8606 as the reason for filing 1040-X. Any recommendations on language so I have a chance at reasonable cause?
