"Is the basis retained for a future year?"
Stevehofwa, no. Despite not preparing Form 8606 correctly, a proportional amount of the basis was distributed when you received the distribution. If the corresponding tax year has not yet closed for a claim of refund you can amend that year's tax return to claim a refund. Otherwise you would just file (or at least prepare) the corresponding Form(s) 8606 to correct the basis that carried forward each year and you have lost the benefit of that basis that you originally failed to report. Line 14 of one Form 8606 carries forward to line 2 of the next Form 8606 that is needed. You'll also need to know the corresponding year-end balance in traditional IRAs for line 6 of each of the Forms 8606 that report distributions.
