Keep in mind also that HSA contributions, IRA contributions, reduce MAGI (essentially the number on bottom row of Page 1 of your annual 1040 Form).
So, as a simple&rough example, assume W-2 income + Interest totals 25,000 for a household of 2 adults and they contributed 3000 to traditional IRA and 1000 to an HSA, then MAGI would be 21,000 and they would qualify for almost nill monthly payment within a Silver Plan which would include a Tax Subsidy AND it would also include a Cost sharing reduction with a modest annual max deduction.
So, as a simple&rough example, assume W-2 income + Interest totals 25,000 for a household of 2 adults and they contributed 3000 to traditional IRA and 1000 to an HSA, then MAGI would be 21,000 and they would qualify for almost nill monthly payment within a Silver Plan which would include a Tax Subsidy AND it would also include a Cost sharing reduction with a modest annual max deduction.