What Is the Last Day to Contribute to an HSA?
Understand the timing and eligibility rules for making an HSA contribution to ensure you can secure your maximum tax deduction for the correct tax year.
A Health Savings Account (HSA) is a tax-advantaged savings account for healthcare expenses, available to those enrolled in a high-deductible health plan (HDHP). It offers a triple tax benefit: contributions are tax-deductible, the funds grow tax-free, and withdrawals for qualified medical expenses are also tax-free.
The HSA Contribution Deadline
The final day to contribute to your Health Savings Account for any given tax year is the same as the federal income tax filing deadline for that year, typically April 15th. If the 15th falls on a weekend or a holiday, the deadline shifts to the next business day. For example, you have until the tax filing day in April 2025 to make an HSA contribution for the 2024 tax year.
This deadline is firm and is not extended even if you file for an extension to submit your tax return. An extension provides more time to file your Form 1040 but does not grant additional time to fund your HSA for the prior year. The contribution must be made by the original tax filing deadline to be deductible on that year’s tax return.
Contribution Rules and Limits
The amount you can contribute to an HSA is governed by annual limits set by the IRS, which are adjusted for inflation. For 2024, individuals with self-only HDHP coverage can contribute up to $4,150. Those with family HDHP coverage can contribute up to $8,300. For the 2025 tax year, these limits increase to $4,300 for self-only coverage and $8,550 for family coverage. These limits include all contributions, whether made by you or your employer.
Individuals age 55 or older by the end of the tax year are permitted to contribute an additional $1,000 as a “catch-up” contribution. If both spouses in a family plan are over 55, each can contribute an additional $1,000 to their own respective HSA, provided they each have an account.
A regulation known as the “last-month rule” allows an individual who becomes HSA-eligible on the first day of the last month of the tax year (December 1 for most people) to contribute the full annual maximum. This applies even if they were not eligible for the entire year. Invoking this rule comes with a requirement: the individual must remain HSA-eligible throughout a “testing period,” which runs from December 1 of the contribution year through December 31 of the following year.
Failing to remain eligible during this 13-month testing period, for reasons other than death or disability, has direct financial consequences. The portion of the contribution that was only possible because of the last-month rule becomes taxable income. An additional 10% tax penalty is also applied to this amount.
Making and Reporting Your Contribution
After determining your eligibility and contribution limit, you can make a direct contribution to your HSA administrator. This is separate from contributions made via payroll deductions, which are handled by an employer. A direct contribution is a lump-sum payment made directly to the financial institution that holds your HSA.
When making a contribution between January 1 and the tax filing deadline, it is important to clearly instruct your HSA administrator which tax year the funds should be applied to. For instance, a contribution made in March could be for the current year or the prior year. This designation is important for accurate tax reporting.
All HSA contributions are reported to the IRS on Form 8889, Health Savings Accounts, which is filed with your annual Form 1040 tax return. This form is used to calculate your HSA deduction and to report distributions. The deduction is then claimed on Schedule 1 of Form 1040, reducing your adjusted gross income.