FSA Calculator 2027: How Much Should You Put In?
Open enrollment is the time to decide. Size your election from your own expenses, see the tax it saves, the share you must spend to break even, and the dates your money expires.
Part 1. How much should you elect?
The rows below are an example. Replace them with what you expect to spend on eligible health costs in the plan year, and mark how sure you are.
How this is chosen: the most you can elect and still break even if only your certain costs happen ($1,000 / (1 - 36.6%) = $1,579, rounded down to whole dollars), never more than certain plus likely ($2,000). Combined rate 36.6%: you break even if you spend at least 63.3% of what you elect.
Forfeiture risk: if only your certain costs happen, $578.00 is at risk. With a grace period you can still use leftover money on new expenses until 2028-03-15.
| Election level | You elect | Net if only the certain items happen | Net if everything happens |
|---|---|---|---|
| Certain expenses only | $1,000 | $367 | $367 |
| Certain plus likely | $2,000 | -$267 | $733 |
| Everything on the list | $2,800 | -$774 | $1,026 |
Net = value of the costs the FSA pays, minus the take-home pay you gave up by electing. Negative means you forfeit more than you save. Tax figures are estimates from the rates you entered.
Part 2. When does your money expire?
Your plan documents set these dates. Enter them to get your deadlines and reminders.
Adds all-day reminders at 60, 30 and 7 days before the last day, plus the last day and the claim deadline. Past dates are skipped.
FSA and HSA limits by plan year
Checked against IRS sources on 2026-10-20. A dash means the IRS had not published the figure; we do not fill it in from estimates.
| Rule | 2026 | 2027 | Source |
|---|---|---|---|
| Health FSA election limit | $3,400 | Not yet published | Rev. Proc. 2025-32 sec. 4.15 (2026) |
| Maximum carryover | $680 | Not yet published | Rev. Proc. 2025-32 sec. 4.15 (2026) |
| Carryover from a plan year beginning in 2025 | $660 | Not applicable | Pub. 969 |
| Grace period | Up to 2.5 months | Up to 2.5 months | Pub. 969 |
| Grace period and carryover together | Not allowed | Not allowed | Pub. 969 |
| HSA limit, self-only / family | $4,400 / $8,750 | $4,500 / $9,000 | Rev. Proc. 2025-19 (2026), Rev. Proc. 2026-24 sec. 3.01 (2027) |
| Dependent care FSA limit | $7,500 | Not yet published | Pub. 15-B (2026) |
How the math works
Electing E dollars lowers your take-home pay by E times one minus your combined tax rate, because the money comes out before tax. If you then spend S on eligible costs, you have covered S of costs you would otherwise have paid after tax. Your net benefit is S minus E times (1 minus rate). It is zero when S equals E times (1 minus rate), which is why the break-even is a share of your election, not of your expenses.
The recommended election is the largest amount that still breaks even if only the costs you marked certain happen: certain costs divided by one minus the rate. The combined rate is your top federal bracket plus the state rate you enter plus the 7.65% payroll tax that salary reductions through a cafeteria plan avoid. State tax is a plain rate input because rates and brackets differ by state; enter your own marginal rate.
If you are choosing between a general-purpose FSA and an HSA, check eligibility first with the HSA vs FSA checker, and see your HSA limit in the HSA contribution limit calculator. If you already have a balance and want ideas, the FSA and HSA product bundle builder lists eligible products.
Sources and date checked
Every number and rule on this page comes from the pages below, read on October 20, 2026. If a source changes, this page can be out of date until it is rechecked.
- IRS Rev. Proc. 2025-32 (2026 inflation adjustments, section 125(i) health FSA limit and carryover)
Section 4.15: the 2026 health FSA limit ($3,400) and maximum carryover ($680). Read 2026-10-20.
- IRS Rev. Proc. 2026-24 (2027 inflation adjusted amounts for HSAs and excepted benefit HRAs)
Section 3.01: 2027 HSA limits ($4,500 self-only, $9,000 family) and HDHP minimum deductible and out-of-pocket maximum. It does not cover the health FSA limit. Read 2026-10-20.
- IRS Publication 969, Health Savings Accounts and Other Tax-Favored Health Plans
Use-it-or-lose-it, the 2.5 month grace period, the $660 carryover from plan years beginning in 2025, and the rule that a plan cannot have both. Read 2026-10-14.
- IRS Publication 15-B (2026), Employer's Tax Guide to Fringe Benefits
Cafeteria plan salary reductions for a health FSA, and the 2026 dependent care FSA limit ($7,500). Read 2026-10-14.
- IRS Publication 15 (2026), Employer's Tax Guide
Social Security and Medicare rates behind the payroll-tax saving. Read 2026-10-14.
Not tax advice. This page is general information built from IRS publications, not advice for your situation. Plan rules, state law and your own facts can change the answer. Confirm with your plan administrator or a tax professional before you act.
Frequently asked questions
How much should I put in my FSA?
Elect what you are confident you will spend on eligible costs, not the maximum. The calculator finds the most you can elect and still break even if only your certain costs happen: your certain costs divided by one minus your combined tax rate. At a 30% combined rate you need to spend at least 70% of your election to come out ahead.
What is the health FSA limit for 2027?
The IRS had not published the 2027 limit when this page was checked on 2026-10-20. The annual inflation adjustment that sets it (section 125(i)) usually comes out in the fall. For plan years beginning in 2026 the limit is $3,400 and the maximum carryover is $680 (Rev. Proc. 2025-32). Your employer will confirm your plan's 2027 limit.
What is the FSA grace period?
A plan may give you up to 2.5 months after the end of the plan year to incur new eligible expenses using the leftover money (IRS Publication 969). For a calendar-year plan that is March 15. A plan with a health FSA carryover cannot also offer the grace period.
How does FSA rollover (carryover) work?
If your plan allows a carryover, leftover money up to a set amount moves into the next plan year and the rest is forfeited. For plan years beginning in 2026 the IRS maximum is $680; for 2027 it had not been published when checked. Many plans set a lower cap, so use the figure in your plan document.
What is the run-out period?
It is the window after the plan year ends in which you can still submit claims for costs you incurred during the plan year. The IRS does not set it; your plan does. It is separate from the grace period, which extends the time you can incur costs.
How are the tax savings calculated?
Your election comes out before federal income tax, state income tax and, for cafeteria plan salary reductions, Social Security and Medicare tax. The calculator multiplies your election by the federal bracket, the state rate you enter and the payroll rate you choose. State rates are not looked up, so enter your own marginal rate. These are estimates, not a tax return.
Can I have an FSA and an HSA?
Not with a general-purpose health FSA. A limited-purpose or post-deductible FSA can sit beside an HSA. For 2027 the HSA limits are $4,500 self-only and $9,000 family (Rev. Proc. 2026-24). The HSA vs FSA eligibility checker walks through your plan.