Taxes · Insurance · Open enrollment
Open enrollment is a plan choice that secretly elects an account. A health FSA is a use-it-or-lose plan-year bucket. An HSA is yours, rolls forever, and needs a qualifying HDHP. A general FSA and an HSA are not a stack. They are a fork. The compounding story lives in the triple-tax primer. This page is the November decision.
Updated 2026-09-08 · 12 min read · Educational, not tax or benefits advice. Run the HSA vs FSA calculator with last year’s billed charges and this year’s SBCs.
| HSA | Health FSA | |
|---|---|---|
| Who owns it | You. It follows a job change. | The cafeteria plan. You leave, it usually dies. |
| 2027 size | $4,500 self / $9,000 family + $1,000 at 55+ | 2026 salary reduction $3,400; 2027 not out yet. Enter the SPD. |
| Use-it-or-lose | No. Balance rolls. Invest above the cash sleeve. | Yes, unless the employer offers grace or a $680-class carryover (2026). |
| Needs | Qualifying HDHP, not on Medicare, not a dependent | A cafeteria election. Copay plans welcome. |
| FICA | Payroll contributions usually skip it | Salary reduction usually skips it |
| Pairing | Limited-purpose FSA (dental/vision) is the legal combo | General FSA + HSA = you are not HSA-eligible that month |
People google “HSA vs FSA” and treat them as two flavors of pretax medical. They are not. Electing a general health FSA next to an HDHP is how you discover in March that the HSA contributions were excess.
Worked slice
HDHP premium $2,160, deductible $1,750, 20% coinsurance. Patient share $2,000. HSA $4,000 employee + $500 employer (the $4,500 cap), combined marginal 29.65%. Net cost about $2,474, and $2,500 can still sit in the HSA if you paid medical from it. PPO premium $4,560, patient share $1,200, FSA $2,000 with $800 wasted: net about $5,967. Premium gap plus the HSA leftover, not the copay, is the story.
The usual “no”
$15,000 billed, HDHP OOP $8,700, PPO OOP $5,000, almost the same employee premium, no employer HSA seed. The PPO can win the cash year even if the HSA would have been a better retirement account. That is a cash-flow decision, not a slogan. The calculator is for that fork.
| Item | 2026 | 2027 |
|---|---|---|
| HSA self-only | $4,400 | $4,500 |
| HSA family | $8,750 | $9,000 |
| HSA catch-up 55+ | $1,000 | $1,000 |
| HDHP min deductible | $1,700 / $3,400 | $1,750 / $3,500 |
| HDHP max OOP (not premiums) | $8,500 / $17,000 | $8,700 / $17,400 |
| Health FSA salary reduction | $3,400 (carryover $680) | Not published as of Sep 2026 |
| Dependent-care FSA | $7,500 ($3,750 MFS) | Statutory; confirm Pub. 15-B |
HSA / HDHP 2027: Rev. Proc. 2026-24 (May 29, 2026). HSA / HDHP 2026: Rev. Proc. 2025-19. Health FSA 2026: Rev. Proc. 2025-32 / Pub. 15-B. Dependent-care $7,500 is the 2026 statutory ceiling after the One Big Beautiful Bill Act, not an HSA number. Direct-primary-care monthly fees up to $150 / $300 do not, by themselves, kick you off the HSA in 2026–27 — still not a license to ignore the SPD.
If the in-network deductible is under the IRS minimum, it is not an HDHP. If the in-network OOP max is over the IRS maximum, it is not an HDHP. Copays that apply before the deductible for non-preventive care can also spoil it. Preventive care can be first-dollar; that is the exception, not a copay clinic.
Family coverage is “anything other than self-only.” Self + child is family for the HSA cap and the HDHP tests. Employer + employee contributions share one cap. A $2,000 seed plus a $4,500 election on a $4,500 self-only limit is $2,000 of excess, not generosity.
You elect the health FSA in November for a plan year that has not started. Known braces, known glasses, a scheduled surgery: those belong in the number. “I might do a bunch of PT” does not. Carryover / grace is a cushion, not a strategy. An HSA you under-fund can still be topped up until the tax-filing deadline; you just lose the FICA skip on the non-payroll slice. That is why payroll is the default for employees.
A limited-purpose FSA is the grown-up combo: HDHP + HSA for medical, tiny FSA for dental and vision so those claims do not raid the compounding bucket. If HR only offers a general FSA, you are choosing.
The triple-tax pitch assumes you can pay a bad year from cash or from the HSA without a 22% card. If the deductible would land on a credit card, the copay plan plus a sized FSA is the less-wrong election even if a blog would have maxed the HSA. Size the cash sleeve first — about 1× the deductible sitting in HYSA, not in the invested HSA.
Medicare enrollment usually ends HSA contributions (the month you are enrolled). Age 65 is not a surprise. The last fully eligible year is a funding year, not a spend-down year. Receipts stay an asset; see the primer.
Free tool
2026 / 2027 caps, HDHP test, light / typical / bad year, FICA + income-tax save, FSA leftover, shareable URL.
PayPal
12-month EOB pull, limited-purpose vs general, payroll vs April 15, Medicare-year cutoff, receipt shoebox.
General FSA: no. Limited-purpose (dental/vision or post-deductible): yes. Dependent-care FSA: unrelated, does not block.
$4,500 / $9,000 plus $1,000 at 55+. Employer money counts. Rev. Proc. 2026-24.
Deductible at least $1,750 / $3,500 and OOP at most $8,700 / $17,400, in-network, premiums excluded. Read the SBC.
Yes. Grace or carryover (2026 carryover $680), not both. 2027 FSA cap was not out in September 2026.
Payroll, usually yes. 1040 contribution, income-tax deduction only. FSA salary reduction also skips FICA.
If the deductible is cashable and the calculator says the typical year plus the light year both win. A disaster year can still favor the PPO.
Educational only. Confirm Rev. Proc. 2026-24, Pub. 969, Pub. 15-B, and your SBC / SPD before you elect. Written by Thomas Sanders.