In 2021 unknown to me I was enrolled in both a New Jersey marketplace health insurance plan and medicaid. I believe this called enrolled in other qualified heath insurance. This apparently occurred during the transition from Healthcare.gov to the NJ Marketplan (GetcoveredNJ.gov) even though I had estimated my income above the medicaid income limit. I did return a form to medicaid July 2021 to terminate the insurance in when I was notified by the NJ Marketplace , but medicaid was still not terminated.
NJ retroactively removed subsidy and I have to pay the full premium to the insurance company for Oct, Nov, and Dec 2021 and is shown on the 1095-a Will I have to repay additional subsidy to the IRS ?
Most likely. When you enter the 1095-A into your tax return the system will add any amount that you have to repay on to your tax bill. So you'll find out pretty quick.
So the amount would be determined by the 1095-a entries into TT and my income. Does the IRS use any other factors to determine the amount owned or penalties ?
Yes, the IRS also considers your Modified Adjusted Gross Income (MAGI) when calculating your Premium Tax Credit (PTC)
MAGI is adjusted gross income (AGI) plus these if any: untaxed foreign income, non-taxable Social Security benefits, and tax-exempt interest. For many people, MAGI is identical or very close to adjusted gross income. MAGI doesn't include Supplemental Security Income (SSI).