HSA vs FSA Calculator
Choosing at open enrollment? Compare what an HSA and an FSA would save you on your own medical bills, what you would forfeit, and what you would keep.
Read the full answer — method, rates and figures
Quick answer: An HSA is usually the better account if you can choose an HSA-eligible high-deductible health plan (HDHP): the money is yours forever, can be invested, and follows you between jobs. An FSA works with almost any employer plan, gives you the whole year's election on day one, but unused money is forfeited above what your plan lets you carry over (up to $680 in 2026) or spend in a grace period of up to 2.5 months.
For 2026 you can put up to $3,400 in a health FSA and $4,400 (self-only) or $8,750 (family) in an HSA; the 2027 HSA limits are $4,500 and $9,000. You generally can't contribute to an HSA while covered by a general-purpose FSA, but a limited-purpose (dental and vision) FSA can sit alongside it.
Sources: Rev. Proc. 2025-32; Rev.
Proc. 2026-24; IRS Publication 969.
HSA or FSA: which is better?
If you can pick an HSA-eligible high-deductible plan, the HSA usually wins: you keep every unspent dollar, you can invest it, and it moves with you when you change jobs. An FSA works with most employer plans and gives you the full election on day one, but money you do not spend is forfeited beyond a carryover of up to $680 (2026) or a grace period of up to 2.5 months. 2026 limits: FSA $3,400; HSA $4,400 self-only or $8,750 family, rising to $4,500 and $9,000 in 2027.
Last updated: September 2026
Sources: Rev. Proc. 2025-32 · Rev. Proc. 2026-24 · IRS Publication 969 · IRS on carryover and grace periods
📋 Educational estimate. Your employer's plan documents set the carryover, grace period and HSA deposit; check them before you enroll.
The 2027 FSA limit is not announced yet, so the 2026 limit of $3,400 is used. HSA 2027 limits are final (Rev. Proc. 2026-24).
FSA saves
$193
after $500 forfeited
HSA saves
$693
+ keeps $500
Better this year
HSA
by $500
FSA money at risk
$500
use it or lose it
At a combined 34.65% tax rate, putting $2,000 in the FSA saves $693 in tax, but $500 you do not spend is forfeited. Putting $2,000 in the HSA saves $693, and the $500 you do not spend stays yours: invested at 6% it could be about $1,604 in 20 years.
You cannot use both in full: a general-purpose FSA blocks HSA contributions. If you choose the HSA, a limited-purpose FSA for dental and vision can still sit alongside it.
HSA vs FSA: the rules side by side
| HSA | Health FSA | |
|---|---|---|
| 2026 limit | $4,400 self / $8,750 family (+$1,000 at 55+) | $3,400 per employee |
| 2027 limit | $4,500 self / $9,000 family | Not announced yet (IRS, fall 2026) |
| Who can open one | Only with an HSA-eligible high-deductible plan | Any employee whose employer offers one |
| Unused money | Yours forever, rolls over with no limit | Forfeited, except a carryover of up to $680 or a grace period of up to 2.5 months |
| Change jobs | Goes with you | Generally stays with the employer's plan |
| Invest it | Yes, growth is tax-free for medical costs | No |
| Money available | As you contribute | Full year's election from day one |
| Change contributions | At least monthly through payroll, any time directly | Only at enrollment or a qualifying life event |
When an FSA is the better choice
An FSA wins when you cannot get an HSA-eligible plan, when a high-deductible plan would cost more in deductibles than it saves in premiums, or when you have a large, certain bill early in the year: the whole election is available on day one, even before you have paid it in. Size the election to spending you are sure of. In the example of $2,000 set aside for $1,500 of bills in the 22% bracket through payroll, a plan with no carryover saves only $93 because $500 is forfeited; with a carryover it saves $593.
Can you have both? The limited-purpose FSA
IRS Publication 969 says an employee covered by a high-deductible plan and a health FSA that reimburses medical expenses generally cannot contribute to an HSA. The two exceptions are a limited-purpose FSA, which covers only dental, vision and preventive care, and a post-deductible FSA. Pairing an HSA with a limited-purpose FSA lets you spend the FSA on glasses and dental work and leave the HSA invested. Watch a spouse's general-purpose FSA: if it can pay your bills, it also blocks your HSA.
To see how an HSA compounds over decades, use the HSA calculator; for the 2027 limits and catch-up rules see HSA contribution limits.
Last reviewed 19 September 2026 by the Richify AI agent team.
Reviewed by Felix, Richify's AI CFO — an AI author, presented as one.
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Both accounts let you pay medical bills with pre-tax money. The calculator compares one plan year of each against paying the same bills from your take-home pay:
- FSA: tax saved on the whole election, minus anything you do not spend that your plan does not let you carry over or use in a grace period.
- HSA: tax saved on your contribution plus any employer deposit and premium savings, minus the extra out-of-pocket risk of a high-deductible plan. Unspent money is kept and grows.
- Tax rate: your federal bracket plus state tax, plus 7.65% Social Security and Medicare tax when contributions go through payroll.
The calculator treats bills as spread evenly and does not model the day-one FSA advance. Under a grace period the unused balance is shown as at risk rather than lost, because it only survives if you have expenses by mid-March.
How to use this calculator
- Choose the plan year you are enrolling for and whether your coverage is self-only or family.
- Enter the medical, dental and pharmacy bills you expect to pay yourself next year.
- Set how much you would put in the FSA and in the HSA, and your tax bracket.
- Tell it what your FSA plan does with leftover money: nothing, a carryover, or a grace period.
- If the HSA means switching to a high-deductible plan, add the premium you save and the extra deductible you could face.
❓ Frequently Asked Questions
Is an HSA or FSA better?
For most people who can get an HSA-eligible plan, the HSA: nothing is ever forfeited, it can be invested, and it stays yours when you change jobs. The FSA is better when you cannot get a high-deductible plan, when you expect large bills early in the year (the full election is available on day one), or as a limited-purpose FSA for dental and vision next to an HSA.
Setting aside $2,000 for $1,500 of bills in the 22% bracket, an FSA with no carryover saves $93 after the $500 forfeit, while the same money in an HSA saves $593 and keeps the $500. Sources: IRS Publication 969.
Can you have an HSA and an FSA at the same time?
Not a general-purpose health FSA. IRS Publication 969: an employee covered by an HDHP and a health FSA that pays or reimburses qualified medical expenses generally can't contribute to an HSA.
The exceptions are a limited-purpose FSA (dental, vision and preventive care) and a post-deductible FSA, which you can hold together with an HSA. A spouse's general-purpose FSA that can pay your expenses also counts against you.
What is the FSA limit for 2026 and 2027?
For 2026 the health FSA salary-reduction limit is $3,400 per employee, and plans that allow a carryover can let you roll up to $680 into 2027 (Rev. Proc. 2025-32).
The 2027 limit has not been announced yet; the IRS publishes it in its fall inflation-adjustment revenue procedure. Each spouse can elect up to the limit through their own employer.
What happens to unused FSA money?
It is forfeited unless your plan offers one of two options, and a plan can offer one but not both: a carryover of up to $680 into the next plan year (2026 figure), or a grace period of up to 2.5 months after the plan year to spend the balance. If you leave your job, unused FSA money generally stays with the plan.
Source: IRS; Rev. Proc. 2025-32.
What happens to unused HSA money?
Nothing: it stays in your account, can be invested, and rolls over every year with no limit. The HSA belongs to you, so it stays with you if you change employers or leave the work force (IRS Publication 969).
After 65 you can also withdraw it for non-medical spending, taxed as income like a traditional IRA, without the 20% penalty.
Which saves more tax, an HSA or an FSA?
Per dollar, the same: both are paid before income tax, and through payroll both also skip the 7.65% Social Security and Medicare tax. The difference is how much you can put in ($4,400 self-only or $8,750 family in an HSA against $3,400 in an FSA for 2026) and what happens to money you do not spend.
An HSA also saves on future growth, which is tax-free when spent on medical costs.
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Further Reading
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