Reconcile Premium Tax Credit Before October 15 Deadline for 2016 Eligibility
Some of your clients who received advanced payment of their Premium Tax Credit may have received an IRS Letter 5591 or 5596 regarding the filing status of their Form 8962, the former to taxpayers who haven't filed the form and the latter to those who requested an extension but haven't filed. They will need a copy of their Form 1095-A to complete the 8962, which can be downloaded from their Marketplace account at Healthcare.gov.
While the extension deadline is October 15, the IRS emphasizes that filing sooner ensures affected taxpayers remain eligible for PTC assistance in 2016.
Source: Internal Revenue Service