Per IRS Publication 17, page 245:
Health coverage tax credit (HCTC). The HCTC is a tax credit that pays a percentage of health insurance premiums for certain eligible taxpayers and their qualified family members. The HCTC and the PTC are different tax credits that have different eligibility rules. If you think you may be eligible for the HCTC, see Form 8885 and its instructions or visit IRS.gov/HCTC before completing Form 8962.
For more information, see the IRS page Health Coverage Tax Credit.