An individual mandate is a requirement that all persons procure a particular good or service. In health care, it refers to the requirement within the Affordable Care Act that most Americans must carry health insurance or pay a tax penalty. The 2018 tax penalty was the greater of either $695 per uninsured adult (and half that amount for a child), or 2.5 percent of household income.
The Supreme Court upheld the ACA’s individual mandate as constitutional in 2012, but the 2017 tax bill eliminated the penalty beginning in 2019. Lacking a federal individual mandate, states can implement their own, as Massachusetts did prior to the ACA.