The IRS issues Letter 12C to inform a taxpayer that their return has been received, but additional information is needed in order to process the return. If your Letter 12C indicates that Form 8962, Premium Tax Credit was missing and not attached to your return, you will need to send the completed Form 8962 to the IRS. You do NOT need to amend your return, so there is no need to submit Form 1040-X, Amended Return. Following this process will ensure a faster refund than mailing the 1040-X to the IRS. This procedure only applies to taxpayers who received a 1095-A.
Taxpayers who purchased health insurance from the marketplace and had advance payments of the premium tax credit paid directly to their insurance provider are required to reconcile these advance payments on Form 8962 with their tax return. Taxpayers should use the Form 1095-A provided by their marketplace to fill out the Form 8962.
The IRS mailing address or fax number will appear on the letter 12C.