Did you get a letter from the IRS (LTR 12C) asking for Form 8962, and possibly other forms? If so, follow the instructions in the FAQ at the following link. At the bottom of the FAQ click the link for the type of TurboTax software that you are using. TurboTax will fill out Form 8962 when you enter your Form 1095-A.
https://ttlc.intuit.com/questions/4348755-the-irs-is-requesting-form-8962-for-2018
Also read the information at the following link on the IRS web site.
https://www.irs.gov/individuals/understanding-your-letter-0012c