HSA contributions in excess of the IRS annual contribution limits ($3,600 for individual coverage and $7,200 for family coverage for 2021) are not tax deductible and are generally subject to a 6% excise tax.
If you’ve contributed too much to your HSA this year, you can do one of two things:
1. Remove the excess contributions and the net income attributable to the excess contribution before they file their federal income tax return (including extensions). You’ll pay income taxes on the excess removed from your HSA.
2. Leave the excess contributions in your HSA and pay 6% excise tax on excess contributions. Next year you may want to consider contributing less than the annual limit to you HSA to make up for the excess contribution during the previous year.