The 1095-A was for me and my wife, i went on Medicare in September. I didn't realize i had 2 forms and only input the information from the 2nd form from the last 3 months. The IRS accepted by return so i am not sure if need to amend it.
If your return was accepted for filing, you don't need to amend it just for one missing Form 1095-A. However, if the missing form affects your balance due or refund, the IRS may send you a letter asking you to correct Form 8962, which is where the information on Forms 1095-A is reconciled to determine whether you owe tax or are due a refund because of the Premium Tax Credit.
To access the Form 1095-A section and update Form 8962, once you have confirmed that your return has been processed (refund received or payment processed):
Fill in the information from the 1095-A and answer all of the questions.
Review your tax return, then go to Tax Tools, Print Center, and print your 2023 tax return as a pdf. Find the Form 8962 in the pdf copy and print that form. Then follow the directions from the IRS to mail or fax the 8962 along with a copy of the 1095-A and a copy of the letter from the IRS.