So, I was wrong. The Obamacare premium is calculated after applying the fedgov subsidy you qualify for.
That’s my understanding...tax credit is based on modified adjusted gross income and family size. So, the premium people will see through the marketplace will be adjusted lower for those who qualify for those tax credits. They can take the tax credit now (which will lower their monthly premiums), or they can wait and receive the credit when they file taxes for the year ending (they pay the full premiums all year but then get reimbursed when filing taxes).
The cost reductions (lower co-pays, lower deductibles) are only available for those with incomes up to 250% of federal poverty level; while the tax credits for the lower premiums are available for those with incomes up to 400% of federal poverty level.