This is from IRS: FAQ from 2015, but I believe it is same for 2020 IE no double dipping
You can claim the HCTC for all qualified health plans offered through a Health Insurance Marketplace , However, you cannot claim both the HCTC and the premium tax credit (PTC) for the same coverage for the same coverage months checked on line 1 of Form 8885. You can only claim PTC for coverage for which you do not elect the HCTC.
This is the link: https://www.irs.gov/credits-deductions/individuals/hctc-claims-faqs
