How Do I Contribute to My HSA: Methods, Limits, and Deadlines

To contribute to an HSA, you move money into the account in one of three ways: pretax payroll deductions through your employer, direct electronic transfers from your bank, or a transfer or rollover from another HSA. For 2026, the IRS caps total contributions at $4,400 for self-only coverage and $8,750 for family coverage, with an extra $1,000 allowed if you are 55 or older, and you have until April 15, 2027, to finish funding the 2026 year.¹

Confirm You Can Still Contribute

Before you deposit anything, check that you still qualify for the month you are contributing for. You need to be enrolled in a High Deductible Health Plan and meet a few other conditions. For 2026, an HDHP has a minimum deductible of $1,700 self-only or $3,400 family, with out-of-pocket costs capped at $8,500 and $17,000.¹

Three things will shut off your ability to make new contributions:

Other disqualifying coverage, including a general-purpose FSA or HRA. A limited-purpose FSA covering only dental and vision is fine.
Enrollment in any part of Medicare. From the first month of enrollment your contribution limit is zero, and retroactive Medicare coverage makes any contributions during that backdated period excess.²
Being claimed as a dependent on someone else’s return.

Starting in 2026, the One, Big, Beautiful Bill Act pulled more people into eligibility. Bronze and catastrophic marketplace plans now count as HDHPs for HSA purposes even if they fall short of the standard deductible or out-of-pocket rules, and the plan does not have to be bought through an Exchange as long as it is a type offered there. Enrolling in a direct primary care arrangement no longer blocks you, and HDHPs can cover telehealth before the deductible without knocking out your eligibility.³

How Much You Can Contribute in 2026

The IRS adjusts the caps each year. For 2026:

Self-only HDHP coverage: $4,400
Family HDHP coverage: $8,750
Catch-up if you are 55 or older: an additional $1,000

These numbers are the ceiling on everything that goes into the account: your money, your employer’s money, and any third-party deposits, all combined.¹ The $1,000 catch-up is fixed by statute and does not adjust for inflation.⁴

If both spouses are 55 or older and neither is on Medicare, each can claim the $1,000 catch-up, but each amount has to go into that spouse’s own HSA. You cannot stack both catch-ups in one account.⁵

Mid-Year Eligibility and the Last-Month Rule

If you became HSA-eligible partway through the year, your limit is normally prorated at one-twelfth of the annual amount for each month you had qualifying HDHP coverage. The last-month rule offers an alternative: if you are eligible on December 1, you can contribute the full annual limit as though you had been eligible all year.²

The catch is a testing period. You have to stay eligible from December 1 of the contribution year through December 31 of the following year. Lose eligibility inside that window (by switching plans or enrolling in Medicare, for example) and the amount above your prorated share gets added back to gross income and hit with a 10% additional tax.⁶

Ways to Put Money In

Payroll Deduction Through Your Employer

If your employer offers HSA contributions through a Section 125 cafeteria plan, this is the most tax-efficient route. The money leaves your paycheck before federal income tax, Social Security tax, and Medicare tax are calculated, so your taxable wages drop across all three.⁷ You file an election form with HR specifying the amount per pay period. Most employers let you change that amount any time during the year, not only at open enrollment.

Direct Deposits From Your Bank

If payroll deduction is not available, or you prefer to fund on your own schedule, you can deposit money straight into the account through your HSA custodian. Most custodians offer an online portal or app where you link an external bank account with routing and account numbers, verify the link (often through small test deposits), and then schedule one-time or recurring electronic transfers. Contributions made this way are still deductible on your return, but they will not reduce your Social Security or Medicare tax the way payroll deductions do.

Transfers and Rollovers From Another HSA

Moving money in from an existing HSA (say, one from a previous employer) does not count against your annual contribution limit. A trustee-to-trustee transfer sends the funds directly between custodians and can be done as often as you like. Alternatively, you can take a distribution and redeposit it into another HSA within 60 days, but that rollover option is available only once every 12 months.⁸

The Contribution Deadline

You can keep funding a tax year until the federal filing deadline of the following April 15. Contributions for 2026, for example, are due by April 15, 2027.² If you deposit money after December 31, tell your custodian which tax year the contribution applies to. Otherwise the amount will land in the current year on your Form 5498-SA.⁹

If You Contribute Too Much

Deposits that exceed your annual limit trigger a 6% excise tax on the excess for every year it stays in the account.¹⁰ You report the tax on Part VII of Form 5329.¹¹

To avoid the penalty, pull the excess out (along with any earnings attributable to it) by the filing deadline, including extensions, for the year you over-contributed. The excess itself comes out clean, but any earnings distributed with it are taxed as ordinary income in the year you receive them.⁴ Ask your custodian for a “return of excess contribution” specifically. They have a dedicated form so the withdrawal is not miscoded as a medical distribution.

Missed the deadline? You can still stop the bleeding by contributing less than your limit in a future year. The gap absorbs prior-year excess and eventually turns off the 6% tax going forward. It does not refund the penalty already paid for earlier years.

Reporting Contributions at Tax Time

Three forms handle HSA activity:

Form 8889 goes with your Form 1040. You use it to report contributions, calculate your deduction, and reconcile distributions. If any HSA contributions were made for the year, this form is required.¹²
Form 1099-SA comes from your custodian and reports distributions. You use it to complete Part II of Form 8889.¹³
Form 5498-SA also comes from your custodian and reports total contributions for the tax year, including anything you deposited between January 1 and April 15 of the following year and tagged for the prior year. You do not file it; keep it with your records.⁹

Payroll contributions made through a Section 125 cafeteria plan are already excluded from the wages shown on your W-2, so do not deduct them a second time on your return. Contributions you make directly, outside of payroll, get reported on Form 8889 and claimed as an above-the-line deduction on Schedule 1, which lowers your adjusted gross income whether or not you itemize.

1
Internal Revenue Service. Rev. Proc. 2025-19 – 2026 Inflation Adjusted Items for Health Savings Accounts
2
Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans
3
Internal Revenue Service. Treasury, IRS Provide Guidance on New Tax Benefits for Health Savings Account Participants Under the One, Big, Beautiful Bill
4
Office of the Law Revision Counsel. 26 USC 223 – Health Savings Accounts
5
Internal Revenue Service. Rules for Married People – IRS Courseware – Link and Learn Taxes
6
Internal Revenue Service. Instructions for Form 8889 (2025)
7
Internal Revenue Service. FAQs for Government Entities Regarding Cafeteria Plans
8
Internal Revenue Service. Rollovers of Retirement Plan and IRA Distributions
9
Internal Revenue Service. Form 5498-SA (Rev. December 2026)
10
Office of the Law Revision Counsel. 26 USC 4973 – Tax on Excess Contributions to Certain Tax-Favored Accounts and Annuities
11
Internal Revenue Service. Form 5329 – Additional Taxes on Qualified Plans Including IRAs and Other Tax-Favored Accounts
12
Internal Revenue Service. Instructions for Form 8889
13
Internal Revenue Service. Instructions for Forms 1099-SA and 5498-SA