Health insurance isn't required by federal law. Five states and Washington, D.C., have their own coverage mandates, and the rules have changed several times since the first one took effect in 2006. Where you live decides whether going without coverage costs you a penalty.
The Affordable Care Act (ACA), the federal law that restructured U.S. health insurance markets, required most Americans to have health insurance from 2014 to 2018. Anyone without it paid a federal tax penalty.
Premiums rise for everyone when only sick people buy insurance. Keeping healthy and sick enrollees in the same risk pool held costs down across the market.
Congress ended the federal penalty in 2019. By then, Massachusetts had required coverage for more than a decade. New Jersey and Washington, D.C., added mandates in 2019, and California, Rhode Island and Vermont followed in 2020.
California's penalty depends on the filing threshold, the income level at which you have to file a tax return. For the 2025 tax year, the threshold for a single filer under 65 with no dependents is $22,941. That filer owes the $950 flat penalty until household income passes $60,941, and above that income, 2.5% of household income over the threshold is the larger amount.








