312
HSA vs 401(k)
Your extra dollars, your brackets, your horizon — the after-match verdict.
X VS Y COMPARISON · MONEY · RETIREMENT
HSA vs 401(k): Where Should Your Next Dollar Go?
You captured the full 401(k) match — smart, that part isn’t a debate. The next dollar is: the health savings account, with its triple tax break, or more 401(k), with its bigger ceiling? At the defaults — $4,400 a year, 25 years, 8% growth, 22% federal + 5% state now, 25% in retirement — the HSA finishes at $321,666.14 of medical-spendable wealth against $241,249.60 after-tax from the 401(k): a $105,023.99 edge, including $24,607.46 of payroll-tax savings most comparisons forget. The catch: the HSA only exists if your health plan qualifies — and the triple break only pays off if you use it for medical costs. Enter your numbers, and read the eligibility test before you move a dollar.
How the after-match order works
The part nobody argues about: fund the 401(k) to the full employer match first — a 50% or 100% instant return beats every tax trick. After the match, the contest is the HSA’s triple tax break (deductible in, tax-free growth, tax-free out for medical) against the 401(k)’s bigger ceiling ($24,500 vs $4,400 in 2026). Both get the same pre-tax deduction going in — the HSA’s extra wins are the 7.65% payroll-tax savings on contributions made through your paycheck and the tax-free medical withdrawals at the end:
| Side | After-tax wealth |
|---|---|
| HSA (medical use, payroll contributions) | $4,400/yr × 25 yrs at 8% = $321,666.14, every dollar spendable tax-free on medical |
| 401(k) (pre-tax) | Same $321,666.14 pre-tax, minus 25% at withdrawal = $241,249.60 |
The $80,416.53 gap is the retirement-rate slice the 401(k) surrenders and the HSA keeps. The extra $24,607.46 is the payroll-tax bonus: HSA contributions through a paycheck skip 7.65% FICA — a benefit no 401(k) or IRA offers — and that saved $336.60/yr compounds for 25 years too. Total HSA edge at the defaults: $105,023.99.
The worked example: $105,023.99, line by line
$4,400 a year beyond the match, 25 years, 8% growth, 22% federal + 5% state now, 25% combined in retirement, HSA used for medical costs:
HSA: $4,400 × the 25-year annuity factor at 8% (73.106) = $321,666.14. Contributions saved $1,524.60 in year-one taxes alone (income tax plus the 7.65% FICA skip), and every dollar of the $321,666.14 can pay medical costs — including Medicare premiums — tax-free, at any age.
401(k): the same $4,400/yr grows to the same $321,666.14 pre-tax, then retirement takes 25% → $241,249.60. No FICA savings, no tax-free exit.
The gap: the HSA wins by $105,023.99 — $80,416.53 of avoided retirement tax plus $24,607.46 of compounded payroll-tax savings. Flip the “use” selector to non-medical after 65 and watch the edge collapse to just the $24,607.46 FICA bonus: past 65, non-medical HSA withdrawals are taxed like a traditional IRA, so the triple break is really a medical-use break. And if you don’t have a qualifying HDHP, the HSA side of this page doesn’t exist — the 401(k) wins by default.
Output · formula · meaning
| Output | Formula | What it means |
|---|---|---|
| HSA after-tax wealth | $C × annuity factor | $321,666.14 at the defaults — medical-spendable, tax-free. |
| 401(k) after-tax wealth | $C × annuity factor × (1 − rret) | $241,249.60 at the defaults — pre-tax growth, taxed on exit. |
| HSA edge | retirement-rate slice + FICA bonus | $105,023.99 at the defaults — the price of skipping the HSA. |
| Year-one tax savings | $C × (fed + state + 7.65%) | $1,524.60 at the defaults — the FICA skip is HSA-only. |
| HSA cap headroom | $4,400 (self) / $8,750 (family) − contributions | 2026 ceilings — the overflow belongs in the 401(k). |
Who uses this
- Open-enrollment choosers: deciding whether the HDHP + HSA combo beats the richer PPO once the tax math is included.
- Max-out planners: sequencing the 2026 waterfall — match, then HSA to the $4,400/$8,750 cap, then back to the 401(k).
- High-bracket savers: the HSA’s edge grows with your marginal rate — at 32%+ federal the FICA bonus alone is serious money.
- Advisors & educators: the payroll-vs-direct FICA distinction is the detail clients miss — cite it with the block below.
Accuracy & limitations
Models after-tax wealth with constant rates and returns; ignores state non-conformity (California and New Jersey tax HSA contributions), employer HSA seed money (counts toward your cap), investment fees, and required minimum distributions (the 401(k) has them from 73; the HSA never does). Assumes HSA contributions flow through payroll — direct contributions lose the 7.65% FICA savings. Assumes medical costs exist to spend the HSA on; a healthy 30-year-old’s real edge includes the shoebox strategy (pay cash now, reimburse decades later — no deadline). Not tax advice.
Cite this calculatorBright Side Kit. “HSA vs 401(k): Where Should Your Next Dollar Go?.” brightoolbox.com, 2026.
Bright Side Kit. "HSA vs 401(k): Where Should Your Next Dollar Go?." https://brightoolbox.com/hsa-vs-401k/ Accessed October 23, 2026.Frequently asked questions
Should I max my HSA before maxing my 401(k)?
After the match: yes, usually. The standard order is 401(k) to the full employer match → HSA to the cap → back to the 401(k). At the defaults the HSA wins by $105,023.99 because it skips both retirement tax (on medical use) and 7.65% payroll tax. The 401(k)’s only advantage is its bigger ceiling — $24,500 vs $4,400 — which is why the overflow goes back there.
What are the 2026 HSA contribution limits?
$4,400 for self-only HDHP coverage, $8,750 for family coverage, plus $1,000 catch-up at 55+ (IRS Rev. Proc. 2025-19). Employer contributions count toward the same cap. Your plan must be a qualifying HDHP: minimum deductible $1,700 self / $3,400 family, out-of-pocket maximum no more than $8,500 / $17,000.
How do I know if my health plan is HSA-eligible?
Run the two IRS tests for 2026: deductible of at least $1,700 (self) or $3,400 (family), and out-of-pocket max at most $8,500 / $17,000. Preventive care before the deductible is fine. Traps: a spouse’s general-purpose FSA that covers you disqualifies you, an embedded per-person deductible under $3,400 on a family plan fails the test, and Medicare enrollment ends eligibility immediately.
Can I really use an HSA as a retirement account?
Yes — it’s the most tax-advantaged one there is. Invest the balance instead of spending it, pay medical bills from cash, and keep the receipts: there’s no deadline to reimburse yourself, so decades of costs become future tax-free withdrawals (the “shoebox strategy”). After 65, non-medical withdrawals are taxed like a traditional IRA with no penalty — the account degrades gracefully instead of expiring.
What kills HSA eligibility?
Four disqualifiers: no qualifying HDHP, other disqualifying coverage (a spouse’s non-HDHP plan covering you, a general-purpose FSA, TRICARE), Medicare enrollment (even Part A alone), and being claimed as a dependent. Lose eligibility mid-year and contributions prorate by month — unless the last-month rule and its 13-month testing period apply.
Is the payroll FICA saving really HSA-only?
Yes. Contributions through your employer’s Section 125 cafeteria plan skip the 7.65% Social Security + Medicare tax — no 401(k), IRA, or direct HSA contribution does that. At the defaults that’s $336.60/yr, compounding to $24,607.46 over 25 years. It’s the most commonly missed line in every HSA-vs-401(k) article.