A central aim of President Obama’s health care law is to expand the number of Americans who have health insurance, and the key to achieving this is through the creation of exchanges in all 50 states, plus the District of Columbia. It’s through these exchanges that individuals will use subsidies (varying by income) to help purchase government-designed insurance policies sold by private companies.

The Congressional Budget Office projected that the exchanges will help 25 million Americans find insurance by 2022, accounting for the bulk of the expanded coverage under Obamacare.