I need to file several delinquent Forms 8606 on a standalone basis for nondeductible contributions I made but did not document on the 8606. I also have a few years where I filed the form but need to correct the Total IRA Basis (line 2 of 8606). Do I need to send backup documentation (e.g. my 1040 pg1, my 5498 form) or is it sufficient to just send the completed/corrected 8606 form for each specific year? Thanks.
