Hello- I noticed that my prior accountant made a few of 8606 mistakes (I should have noticed) over the past 10 years, all 2017 tax year and prior and all related to annual after-tax contributions to a tIRA. One year no 8606 to report the contribution, one year an incorrect value shown in 8606, and one year a completed 8606 with a value shown but I did not make the contribution.
Can this be corrected? If yes, can I submit one corrected 8606 for the 3 mistakes or will it require one Form 8606 for each year? Any advice would be greatly appreciated!