There are two types of subsides-
- Cost Sharing Reductions or CSR. These are subsides available only for Silver tier plans and lower the amount that you spend out of pocket when you seek care.
- Premium Tax Credits or PTC. These are subsidies available on all plans and they lower the amount that you are required to pay in premiums. The amount can be applied monthly, resulting in a APTC (advanced PTC).
Both subsidies are available only if you do not qualify for other coverage, and are based off of your household income in comparison to your household size.
You can read more about subsidies and how they are calculated here.