who said? if it was the IRS sending you a notice that you need to submit 8962, the question becomes did you have health insurance from the Marketplace (Affordable Care Act aka Obamacare) in 2018? if not, did you have health insurance during all of 2018?
if you had Marketplace insurance, then with your return you should have submitted form 8962 which would have been completed from the information on form 1095-A that you should have received. (you probably can download it from the Marketplace website) get it, complete 8962 and submit both with notice.
if you had non marketplace health insurance you should have received form 109-B. write back to IRS that you didn't have marketplace insurance but did have other insurance. submit a copy of 1095-B
if you didn't have health insurance, then write back to IRS you had no health insurance for 2018.
i'm seeing many posts from taxpayers where IRS is requesting 8962 and 1095-A. i don't know whether the problem is IRS computers (the Marketplace would have sent the IRS info they're now asking for.
or taxpayers not answering or incorrectly answering the questions TT asks about health insurance coverage.
