Even if you have maintained eligibility for premium tax credits based on your household income and enrollment in a marketplace plan, your tax credit can still be “shut off,” if you have not filed a federal income tax return. Every year, if you have received premium tax credits of any amounts or if you plan to claim the tax credits, you must file a Form 8962 with your federal income tax return. If you do not file a tax return, you will not be eligible for premium tax credits.
Starting in 2018, the marketplaces are not required to notify consumers of the precise reason for discontinuation, so you might not have been made aware of this issue. To reinstate your premium tax credits, you must file the Form 8962 and reconcile the credits received in past years. Once you have done that, you should return to the marketplace to update your application in order to attest that you have filed and reconciled tax credits received in the past. (IRS, Questions and Answers on the Premium Tax Credit; HHS, Notice of Benefit and Payment Parameters for 2019; CMS, Working With Consumers Who Have NOT Filed Taxes or Reconciled APTC from Prior Years: Overview of the FTR Recheck Process).