Under the Affordable Care Act (ACA), everyone in the U.S. is required to have health insurance. If you don’t, you may have to pay a penalty fee.
If you didn’t have health insurance for all or part of 2018 (which you file taxes for in 2019), and you don’t qualify for an exemption to this requirement, you will have to pay a fee. This also applies to tax years 2016 and 2017. The fee depends on your household size and income. If you don’t pay the fee, the IRS will withhold the amount of the fee from any future tax refunds.
Starting in 2019 (which you file taxes for in 2020), you’ll no longer be required to pay a fee when you file your federal taxes if you don’t have health insurance. Some states still have health insurance requirements.