How contributions work: the three ways to fund your HSA

You can put money into your HSA in three ways: through payroll deduction if your employer offers it, by sending a direct transfer from your bank account, or by mailing a check to your HSA custodian. Payroll deduction is the most common route because the money comes out before taxes are calculated on your paycheck—meaning you save on federal income tax, Social Security tax, and Medicare tax all at once. If you don't have an employer plan, you can still contribute by transferring money yourself from your checking or savings account, though you won't get the payroll tax savings.

The custodian is the financial institution that holds your HSA—often a bank, credit union, or investment company. Your employer either chooses the custodian for you, or if you opened an HSA on your own, you picked one when you set it up. That custodian is who you contact to make contributions, and they're also who sends you the tax forms you'll need at the end of the year.

Contributions are limited by law. For 2024, the limit is $4,150 if you have individual coverage or $8,300 if you have family coverage. These limits change each year, and your custodian or employer will tell you the current year's limit. If you're 55 or older, you can contribute an extra $1,000 per year on top of the standard limit—this is called a catch-up contribution.

Key Takeaways

  • Payroll deduction saves you the most money because contributions avoid federal income tax, Social Security tax, and Medicare tax.
  • If your employer doesn't offer payroll deduction, you can transfer money from your bank account to your HSA custodian yourself.
  • Annual contribution limits are $4,150 for individual coverage and $8,300 for family coverage in 2024, with an extra $1,000 allowed if you're 55 or older.
  • You must have an HSA-may have access to high-deductible health plan to contribute, and you cannot contribute if you're covered by Medicare or claimed as a dependent on someone else's taxes.

Setting up payroll deduction through your employer

If your employer offers an HSA, they will have a payroll administrator or benefits team who handles the setup. You'll typically fill out a form—either on paper or through an online benefits portal—that tells payroll how much to deduct from each paycheck. This amount should be spread across the year so you don't exceed the annual limit. For example, if the limit is $4,150 and you're paid biweekly, you could deduct about $160 per paycheck.

The deduction starts on the date you specify, usually the next pay period after you submit the form. Your employer sends the money to your HSA custodian, and it appears in your account within a few business days. You'll see the deduction on your pay stub as a pre-tax reduction, which means your gross pay goes down but your taxable income goes down by the same amount.

If you want to change the amount mid-year, contact your payroll or benefits department. Most employers allow changes during open enrollment or if you have a may have access to life event—like a change in health coverage, marriage, or birth of a child. Outside those windows, you may have to wait until the next enrollment period.

Making contributions on your own if you don't have employer payroll

If you opened an HSA independently or your employer doesn't offer payroll deduction, you can transfer money from your personal bank account. Log into your HSA custodian's website or call their customer service line and request a transfer. Most custodians allow you to link your checking or savings account and set up either a one-time transfer or recurring monthly transfers.

The transfer usually takes three to five business days to complete. Some custodians also accept checks mailed directly to them—the envelope will have a specific address listed on their website or your account statements. If you mail a check, write your HSA account number on the check and allow one to two weeks for it to clear and post to your account.

When you contribute on your own, you don't get the payroll tax savings automatically. However, you can still claim the contribution as a tax deduction on your federal income tax return using IRS Form 8889. This means you'll file your taxes, report the contribution, and reduce your taxable income by that amount. You'll need to keep records of all contributions you made—bank statements, transfer confirmations, or canceled checks—to back up the deduction if the IRS asks.

Catch-up contributions if you're 55 or older

Once you turn 55, you're allowed to contribute an additional $1,000 per year to your HSA on top of the standard limit. This extra amount is called a catch-up contribution and is designed to help people save more for health care in retirement. The $1,000 is a fixed amount set by law and does not change year to year.

If you contribute through payroll, your employer's benefits team can adjust your deduction to include the catch-up amount. If you contribute on your own, you simply add $1,000 to your annual contribution total when you calculate how much to transfer. For example, if the standard limit is $4,150 and you're 55 or older with individual coverage, your total limit is $5,150.

You can make catch-up contributions for as long as you remain may be able to access—meaning you still have an HSA-may have access to high-deductible health plan and you're not yet on Medicare. Once you enroll in Medicare, you can no longer contribute to an HSA, though you can still withdraw money from it for may have access to medical expenses.

Deadlines and timing for contributions

Contributions for a given tax year must be made by the tax filing deadline—typically April 15 of the following year. For example, contributions for the 2024 tax year can be made anytime from January 1, 2024, through April 15, 2025. If you contribute after the calendar year ends but before the tax deadline, you can still claim that contribution on your tax return for the previous year.

If you contribute through payroll, the money comes out throughout the year as you receive paychecks, so timing is automatic. If you contribute on your own, you can spread contributions across the year or make one lump sum contribution at any point before the deadline. There's no penalty for contributing early or late, as long as you stay within the annual limit and meet the deadline.

If you accidentally contribute more than the annual limit, you'll need to withdraw the excess amount plus any earnings it generated. Your custodian can help you calculate this, and you'll report it on your tax return. Excess contributions that aren't withdrawn are subject to a 6% excise tax each year they remain in the account, so it's worth correcting the mistake promptly.

What happens if you lose HSA may be able to access mid-year

You must have an HSA-may have access to high-deductible health plan to contribute to an HSA. If you switch to a different type of health plan—such as a standard PPO or HMO—you lose may be able to access immediately. You can still withdraw money from your HSA for may have access to medical expenses, but you cannot make new contributions for the rest of that year.

If you've already contributed for the full year through payroll and then lose may be able to access, you may have contributed more than allowed. Contact your payroll department or HSA custodian to report the change. They can help you determine whether you need to withdraw the excess contribution and recalculate your tax situation. The IRS allows a grace period of up to two and a half months after you lose may be able to access to withdraw excess contributions without penalty, though you'll still owe income tax on the excess amount.

If you regain HSA may be able to access later in the year—for example, by switching back to a high-deductible plan—you can resume contributions, but only for the months you're actually may be able to access. Your custodian can help you calculate the pro-rated limit for the remaining months of the year.

Frequently Asked Questions

Can I contribute to an HSA if I'm on Medicare?

No. Once you enroll in Medicare, you're no longer allowed to make new contributions to an HSA. However, you can still withdraw money from your existing HSA balance for may have access to medical expenses. If you contributed for the month you enrolled in Medicare, you may need to withdraw that contribution and report it on your taxes.

What if I contribute too much by accident?

Contact your HSA custodian immediately. You can withdraw the excess contribution plus any earnings it generated before the tax filing deadline. If you don't withdraw it, you'll owe a 6% excise tax on the excess amount for each year it stays in the account, plus income tax on the earnings.

Do I have to contribute the same amount every month?

No. If you contribute through payroll, you can change your deduction amount during open enrollment or after a may have access to life event. If you contribute on your own, you can transfer any amount at any time, as long as your total for the year doesn't exceed the limit.

Can I claim my own contributions as a tax deduction if I contributed through payroll?

No. Payroll contributions are already deducted before your taxes are calculated, so you don't claim them again on your tax return. Only contributions you make on your own—by transferring from your bank account or mailing a check—are claimed as a deduction using IRS Form 8889.

What if my employer changes HSA custodians?

Your employer will notify you of the change and provide instructions for moving your account. You can usually transfer your existing HSA balance to the new custodian without tax consequences. Your payroll deduction will continue with the new custodian, though you may need to re-enroll or confirm your contribution amount.