I assume you received premium subsidies for an exchange policy in 2016, with an estimated annual income that put you into the subsidy range, but your real income fell short of the subsidy range. Now you are worried you will retroactively lose the insurance coverage you had or have to repay the subsidies you received?Good news, nobody will come after you for all of your insurance bills. Bad news, you may have to repay a small portion of the subsidies you received - but not all of them.First off, having received premium tax credits for 2016 makes it mandatory for you to file a 2016 federal income tax return, regardless of your income. If you haven’t already, you should do that before you get into trouble.In addition to the standard 1040 tax form, you will file form 8962 (https://www.irs.gov/pub/irs-pdf/...) to reconcile the advanced premium tax credits (“subsidies”) you received with the real amount of premium tax credits you are entitled to.If you earned below 100% of the poverty line and you are a US citizen, you were not entitled to any premium-tax credits. (Non-citizens below the poverty line often do qualify for premium tax credits if they are ineligible for Medicaid.)Fortunately, there’s a repayment limit that’s tied to your income. If your income was below 200% of the federal poverty line, you will have to repay at most $300 (single filer) or $600 (everyone else) for the year. That’s explained in the instructions for form 8962 (table 5 on page 14): https://www.irs.gov/pub/irs-pdf/...Good luck!