Start with what you'll actually spend on health care this year
The amount you put into your Health Savings Account (HSA) should match the medical costs you expect to pay out of pocket — the money that comes from your own pocket before insurance kicks in or after it stops covering something. This is different from how much you're allowed to contribute, which is a legal limit set each year.
To figure out your expected costs, look at your insurance plan's deductible (the amount you pay before insurance starts helping), any regular prescriptions you take, ongoing doctor visits, dental work you know is coming, or glasses and contacts. If you have a chronic condition like diabetes or asthma, add in the costs of managing that throughout the year. Add up what you think you'll actually spend.
That number is your target. There's no penalty for putting in less than the legal limit — the limit is a ceiling, not a requirement. If you expect to spend $2,000 out of pocket this year, putting in $2,000 makes sense. If you expect $4,000, aim for $4,000.
Key Takeaways
- Contribute only what you expect to spend on medical costs you'll pay yourself, not the legal maximum unless your situation actually requires it.
- The legal contribution limit changes each year and depends on whether your plan covers just you or your whole family.
- Money left over at the end of the year stays in your account and rolls forward — you don't lose it.
- If you're healthy and rarely see a doctor, a smaller contribution protects your money while still giving you a tax break.
- You can change your contribution amount once a year during open enrollment, or if your life changes (marriage, new job, birth of a child).
Understanding the annual contribution limits
The IRS sets a maximum amount you can put into an HSA each year. For 2024, that limit is $4,150 if the plan covers only you, or $8,300 if it covers you and your family. These numbers change slightly each year — the IRS announces the new limits in the fall for the following year.
The limit applies to all your HSA contributions combined in a single year. If you have an HSA through your employer and they contribute $1,000, and you contribute $2,000 from your paycheck, that's $3,000 total — still under the $4,150 limit for individual coverage. You cannot exceed the limit even if you have multiple HSAs or multiple employers.
If you're 55 or older, you can contribute an extra $1,000 per year on top of the regular limit. This "catch-up" contribution is designed to help people build up savings as they approach retirement and expect higher medical costs.
How employer contributions affect your decision
Many employers contribute money to their employees' HSAs as part of the benefits package. This is information programs — it counts toward your annual limit, but it doesn't come from your paycheck. If your employer puts in $1,500, you have $2,650 left to contribute yourself (assuming individual coverage and the 2024 limit of $4,150).
Check your benefits paperwork or ask your HR department exactly how much your employer contributes and when they deposit it. Some employers contribute a lump sum at the beginning of the year; others spread it across paychecks. Knowing this helps you decide how much to add from your own pay.
If you're self-employed or your employer doesn't offer an HSA, you contribute the full amount yourself. You can deduct this contribution from your taxes, which is one of the main reasons an HSA is valuable.
Why you might contribute less than the maximum
Contributing the full legal limit makes sense only if you expect to spend that much or if you want to save extra for future medical costs. If you're young and healthy with minimal medical expenses, a smaller contribution still gives you the tax benefit without tying up money you might need elsewhere.
Consider your emergency fund first. If you don't have three to six months of living expenses saved outside your HSA, putting extra money into the HSA might not be the best choice. HSA money is meant for medical costs — you can withdraw it for other reasons, but you'll pay taxes and a 20% penalty if you're not yet 65.
If you're uncertain about your medical needs for the year, start conservatively. You can increase your contribution next year during open enrollment if you realize you underestimated. The money in your account rolls forward indefinitely, so there's no rush to use it all in a single year.
Building up savings for future medical costs
Once you've covered your expected costs for this year, you might consider putting in more if you can afford it. Money left in your HSA at the end of the year doesn't disappear — it stays there earning interest (though the interest rate is usually small). Over time, this becomes a medical savings account you can draw from in future years.
Some people use their HSA as a long-term investment for retirement. After age 65, you can withdraw HSA money for any reason without the 20% penalty — you'll just pay income tax on non-medical withdrawals, the same as a regular retirement account. This makes an HSA a powerful tool if you can afford to contribute more than you spend each year.
However, this strategy only works if you have money left over after covering your current medical costs and maintaining an emergency fund. Don't sacrifice financial security now for the possibility of a larger medical fund later.
Adjusting your contribution if your situation changes
You can change your HSA contribution amount during your employer's open enrollment period, which usually happens once a year in the fall. You can also make changes if a may have access to life event occurs — marriage, divorce, birth of a child, loss of health insurance, or a significant change in your expected medical costs.
If you change jobs, your new employer's HSA is separate from your old one. You keep the money in your old account, but you'll contribute to the new account going forward. Make sure you understand both plans' deductibles and expected costs before deciding how much to contribute to the new account.
If you realize mid-year that you've contributed too much or too little, you're generally stuck with that amount until the next open enrollment period. This is another reason to estimate carefully at the beginning of the year.
Common mistakes in choosing an HSA contribution amount
The biggest mistake is contributing the maximum just because it's allowed. The legal limit exists to prevent abuse, not to suggest you should use it. If you contribute $8,300 but only spend $2,000 on medical care, you've tied up $6,300 that could have been in a regular savings account or emergency fund.
Another mistake is forgetting about employer contributions. If you assume you're contributing the full amount yourself and your employer is also contributing, you might accidentally exceed the legal limit — the IRS will require you to withdraw the excess and pay taxes on it.
Some people also underestimate their medical costs. If you take regular prescriptions, see a therapist, or wear glasses, add those up before deciding on a number. A quick review of last year's medical bills gives you a realistic picture of what to expect.
Frequently Asked Questions
What happens if I contribute too much to my HSA?
If you exceed the annual limit, the IRS requires you to withdraw the excess amount. You'll pay income tax on the withdrawal, plus a 6% penalty tax on the overage. Contact your HSA provider as soon as you realize the mistake — they can help you file the correction with the IRS.
Can I change my contribution amount mid-year?
Only if you have a may have access to life event like marriage, birth, or job loss. Otherwise, you're locked into your contribution amount until the next open enrollment period. This is why estimating carefully at the beginning of the year matters.
Do I have to spend all the money in my HSA each year?
No. Money left over rolls forward to the next year indefinitely. You can let it accumulate and use it for medical costs in future years, or even save it for retirement after age 65.
Should I contribute more if I expect a big medical expense?
Yes, if you know you'll need surgery, dental work, or other significant care this year, increase your contribution to cover it. The money you put in reduces your taxable income, which is a real financial benefit.
What if my employer contributes to my HSA — do I still need to add my own money?
Not necessarily. If your employer's contribution covers your expected medical costs, you don't have to add anything. But if you expect to spend more than they contribute, adding your own money makes sense.