How is the additional tax on excess contributions to Health Savings Accounts (HSA) calculated?
Excess contributions to an HSA are any amount contributed over the annual limit of $8,550 (Family) or $4,300 (Single). If you have both a family and single HSA (between 2 spouses) you still cannot go over the total family limit. The only exception is the $1,000 additional contribution for those over 55.
The additional tax is 6% of the smaller of your excess contributions or the value of your HSA(s) on December 31, 2025 (including 2025 contributions made in 2026).
For example: Between the employer, taxpayer, and spouse, they contributed $500 too much in 2025. However, the family regularly uses their HSA card for medical bills and rarely have a balance in their account. On December 31st they had just $100 in it. The additional tax would be $6 ($100 x .06).
Otherwise, they would have an additional tax of $30 ($500 x .06).
To reduce or eliminate your additional tax, you can withdraw some or all of the excess contributions before the filing deadline.
Another option is to leave it and pay the additional tax but then apply the overcontribution to the following year. Just be sure to count it in the following year contributions so you don't go over again.
For Example: The $500 from above was not withdrawn by the filing deadline so they paid the $30 additional tax with their return. Then they subtracted it from the family limit for 2026.
That leaves them $8,550 - $500 to contribute for 2026.
How do I split HSA contributions between spouses?
The additional tax is 6% of the smaller of your excess contributions or the value of your HSA(s) on December 31, 2025 (including 2025 contributions made in 2026).
For example: Between the employer, taxpayer, and spouse, they contributed $500 too much in 2025. However, the family regularly uses their HSA card for medical bills and rarely have a balance in their account. On December 31st they had just $100 in it. The additional tax would be $6 ($100 x .06).
Otherwise, they would have an additional tax of $30 ($500 x .06).
To reduce or eliminate your additional tax, you can withdraw some or all of the excess contributions before the filing deadline.
Another option is to leave it and pay the additional tax but then apply the overcontribution to the following year. Just be sure to count it in the following year contributions so you don't go over again.
For Example: The $500 from above was not withdrawn by the filing deadline so they paid the $30 additional tax with their return. Then they subtracted it from the family limit for 2026.
That leaves them $8,550 - $500 to contribute for 2026.
How do I split HSA contributions between spouses?
