If a state doesn’t operate its own exchange for health-care benefits, citizens who want to get covered should visit the federally-run exchange, HealthCare.gov. For the 2015 plan year, 27 states with federally facilitated exchanges, seven states in partnership with the federal goverment and three state-based exchanges will use this site. Click here to check the status of specific states.
Whether they buy a plan through the federal marketplace or an exchange in their state—or qualify for Medicaid—everyone must enroll in a plan or pay a penalty. Even those who purchased plans in the marketplace last year must re-enroll and purchase or select another plan this year because plans have changed and premiums are determined by age and other factors that can change.
Two types of subsidies are available to marketplace enrollees. The premium tax credit reduces enrollees’ monthly payments for insurance coverage. The cost-sharing subsidy is designed to minimize enrollees’ out-of-pocket costs when they go to the doctor or have a hospital stay. Here is a useful Kaiser Family Foundation brief that explains the subsidies.
Here is the foundation's embeddable Health Insurance Marketplace Calculator: