I filed my 2017 taxes with TT, the IRS has now sent me a letter stating they want a copy of my 1095-A and for me to fill out an 8962 form and send them back.
I don't have a 1095-A, but rather a 1095-B. The instructions online here indicate I don't have to do anything with the 1095-B, and that I am exempt at 21K income regardless.
So how do I address this.
Why did TT trigger this in the first place?
I'm just guessing here, as while I am familiar with the health care stuff, I'm not all that "up to snuff" on it. But it sounds to me like you may have had insurance from multiple providers during the tax year, or you have a dependent or spouse that had different insurance or no insurance. But that's just a guess.
Barring any other responses in this thread from someone more knowledgeable on this, I would suggest you call the number provided to you in the letter you received, and ask for clarification. It's also possible the IRS made a mistake, as most likely the letter you got was computer generated and never seen or touched by a human at the IRS, and you are the first set of human eyes to actually see it.
I can only guess that you clicked a box that answered YES to indicate that you had your insurance through the ACA marketplace insurance program. If you had insurance from the marketplace, then you probably had a subsidy and you would need get the 1095-A and complete the 8962 to balance out the subsidy.
Do not ignore the letter. Look at the letter from the IRS to see if they give a contact method for you to respond. If you did not have marketplace insurance for any month, then take action to inform the IRS that there was an error in your submission and you did not have any marketplace insurance at any time during the year. On the other hand, if you had any marketplace insurance (even in you had other insurance), you should contact the marketplace insurance office and take action to get the 1095-A.