Here is another solution. No need to mail in, takes way too long. I had this issue and efile was rejected 4 times even though I knew I entered the correct amount in the "correction" AND this correct amount is exactly what the IRS had in my records. (I was surprised to see that all of my tax records and everything the IRS has was instantly available if you register and log in at IRS.gov) The problem was that no matter what correct number we entered TurboTax was secretly sending another (wrong) number along with the corrected attempts. In my case when TurboTax went to its "Let us help you correct this" page there was a proposed number in the correction box, which was slightly different from the correct one we were trying to submit. (We did try submitting this recommended but wrong number but also rejected). So why did TurboTax have a wrong number even though we filed with TurboTax last year? I think TurboTax picked up a draft return on import rather than the official filed one. Doesn't matter, here is the solution that worked for me.
SOLUTION: Go to Forms and look at your Two Year Comparison and Tax History forms down at the bottom. If the wrong number is shown for last year's AGI fix it by either typing over it if that is allowed or right-click and OVERRIDE it with the correct number. Just that one field. Bingo! Accepted.
