Quick Answer
Choose an HSA if you are enrolled in a qualifying high-deductible health plan (HDHP). HSA money rolls over forever, moves with you between jobs, and can be invested. Choose an FSA if your plan is not an HDHP, or you want to fully fund a predictable near-term medical or dependent care cost, since FSA money is generally use-it-or-lose-it within the plan year. You typically cannot fund a standard HSA and a standard health FSA in the same year, so this is usually an either/or decision during open enrollment.
1. The Core Difference
Both accounts let you set aside pre-tax money for healthcare costs, but they behave very differently once open enrollment ends.
An HSA is yours. It requires you to be enrolled in an HDHP, but once funded, the balance never expires, it earns interest or investment returns, and it stays with you even if you switch employers or health plans.
An FSA is tied to your employer's plan year. You elect an amount during open enrollment, the full amount is available to you on day one of the plan year even though you contribute gradually through payroll, and in most cases unused money above any employer-permitted carryover is forfeited when the plan year ends.
2. 2026 Contribution Limits
| Account | 2026 Limit | Notes |
|---|---|---|
| HSA, self-only coverage | $4,400 | Plus $1,000 catch-up if age 55+ |
| HSA, family coverage | $8,750 | Plus $1,000 catch-up if age 55+ |
| Health FSA | $3,400 | Up to $680 carryover if your employer's plan allows it |
| Dependent Care FSA | $7,500 | $3,750 if married filing separately |
Figures reflect 2026 IRS limits as reported at time of publication. Always confirm against the current IRS guidance and your plan documents, since limits are adjusted annually and legislation can change dependent care FSA limits.
3. Deadlines You Cannot Miss
HSA contribution deadline: You can contribute to an HSA for the 2026 tax year any time between January 1, 2026 and April 15, 2027, the standard federal tax filing deadline. This deadline holds even if you file for a personal extension. When you contribute between January 1 and April 15, tell your HSA provider which tax year the contribution applies to.
FSA use-it-or-lose-it rule: Unless your employer's plan offers a carryover (up to $680 for 2026 health FSA plans that allow it) or a grace period of up to two and a half months, any unspent health FSA balance is forfeited at the end of the plan year. Employers choose which option, if any, to offer, and cannot offer both a carryover and a grace period in the same plan.
4. Who Should Choose an HSA
- You are eligible for a qualifying HDHP. This is a hard requirement. You cannot open or contribute to an HSA without HDHP coverage.
- You want a long-term, investable healthcare fund. Many HSA providers let you invest balances above a set threshold, similar to a retirement account, and unused funds keep growing tax-free.
- You value portability. An HSA is yours regardless of employer changes, unlike an FSA, which is tied to your current employer's plan year.
- You want a backup retirement account. After age 65, HSA funds can be withdrawn for any purpose without penalty, though non-medical withdrawals are taxed as ordinary income, similar to a traditional IRA.
5. Who Should Choose an FSA
- Your employer does not offer an HDHP. If HSA eligibility is off the table, a health FSA is often the only pre-tax option for routine medical costs.
- You have predictable, near-term expenses. Orthodontia, planned surgery, or routine prescriptions you already know you will need this plan year make the use-it-or-lose-it risk manageable.
- You need dependent care support. A Dependent Care FSA covers daycare, preschool, and similar costs and has no HSA equivalent.
- You want the full election available immediately. Unlike an HSA, your full annual FSA election is available to spend from day one of the plan year, even though you have not finished contributing it through payroll yet.
6. Run the Numbers Before You Decide
Before you finalize your open enrollment elections, estimate your realistic medical spending for the coming year against each plan's premium, deductible, and out-of-pocket maximum. If you are already leaning toward an HDHP for the lower premium, our HSA Maximizer calculator can help you model contribution strategy, investment growth, and the long-term tax advantage of maxing out your HSA instead of just covering this year's expenses.
Try the HSA Maximizer calculator to see how consistent HSA contributions and investment growth compare to simply spending the money as you go.
Frequently Asked Questions
Should I choose an HSA or FSA for 2026?
Choose an HSA if you are enrolled in or eligible for a qualifying high-deductible health plan, since HSA funds roll over every year, stay with you if you change jobs, and can be invested for the long term. Choose an FSA if your employer does not offer an HDHP, or if you want to fully fund a known, near-term medical or dependent care expense, since FSA funds generally must be used within the plan year subject to your employer's carryover or grace period rules.
What are the 2026 HSA contribution limits?
For 2026, the IRS limit is $4,400 for self-only HDHP coverage and $8,750 for family coverage. People age 55 and older can contribute an additional $1,000 catch-up contribution.
What are the 2026 FSA contribution limits?
For 2026, the IRS health FSA pre-tax contribution limit is $3,400, with up to $680 allowed to carry over into the next plan year if your employer's plan permits carryover. The dependent care FSA limit is $7,500 for most filers, or $3,750 if married filing separately.
What is the HSA contribution deadline for the 2026 tax year?
You can contribute to an HSA for the 2026 tax year until the federal tax filing deadline, April 15, 2027. This deadline does not extend even if you file for a tax extension.
Do FSA funds roll over, or is it use-it-or-lose-it?
FSAs are generally use-it-or-lose-it. Some employers offer a carryover of a limited amount (up to $680 for 2026 plans that allow it) into the next year, or a grace period of up to two and a half months to spend remaining funds, but not both. Check your specific plan documents, since employers are not required to offer either option.
Can I have both an HSA and an FSA at the same time?
Generally no, not a standard health FSA alongside an HSA, because FSA coverage can disqualify you from HSA eligibility. Some employers offer a Limited Purpose FSA, which only covers dental and vision expenses, and this type can typically be paired with an HSA. Confirm the FSA type with your HR or benefits team before enrolling in both.