HSA vs 401(k) Comparison Calculator

The Triple Tax Advantage of an HSA

Health Savings Accounts (HSAs) are the only tax-advantaged account in the US tax code with three distinct tax benefits: (1) Pre-tax contributions reduce your taxable income (also exempt from FICA payroll tax if contributed via employer payroll deduction); (2) Tax-free growth — investment earnings inside the HSA are never taxed; (3) Tax-free withdrawals for qualified medical expenses at any age. No other account type offers all three (source: IRS Publication 969).

For 2026, HSA contribution limits per IRS announcement: $4,400 self-only coverage and $8,750 family coverage, with an additional $1,000 catch-up for age 55+. Eligibility requires enrollment in a high-deductible health plan (HDHP) — minimum deductible $1,650/$3,300 in 2026, out-of-pocket max $8,300/$16,600.

Why HSA Beats 401(k) for Medical Spending in Retirement

Per Fidelity's 2024 Retiree Health Care Cost Estimate, the average 65-year-old couple needs roughly $315,000-$330,000 saved for medical costs in retirement (source: fidelity.com). If you withdraw $315,000 from a Traditional 401(k) for medical bills, you pay federal income tax (typically 12-22% in retirement) — losing $40,000-$70,000 to taxes. The same withdrawal from an HSA for qualified medical expenses is 100% tax-free.

For non-medical retirement spending, an HSA after age 65 acts like a Traditional 401(k) — withdrawals are subject to ordinary income tax but no penalty. So the HSA wins on flexibility: it covers medical tax-free OR non-medical at the same tax treatment as a 401(k). The 401(k) does not have the medical tax-free option.

The Match Exception — Always Capture Your 401(k) Match First

Despite the HSA's triple tax advantage, the standard hierarchy is: (1) 401(k) up to full employer match first — this is a 50-100% instant return, the best deal in personal finance; (2) HSA to limit if you have HDHP eligibility — capture the triple tax benefit; (3) Roth IRA if eligible (income limits apply); (4) 401(k) beyond the match up to the $23,500 (2026) limit.

This calculator lets you compare contributing the SAME dollar amount to either HSA or 401(k) (after match) so you can see which wins after the full retirement timeline. Use our Traditional vs Roth IRA calculator for the IRA decision and HSA investment growth calculator to project HSA-only growth across multiple decades.

2026 HSA and 401(k) Limits, Plus SECURE 2.0 Updates

2026 limits per IRS guidance: HSA self $4,400, HSA family $8,750, 401(k) elective deferral $23,500 ($31,000 with catch-up at 50+, $34,750 with new "60-63 super catch-up" under SECURE 2.0). Note that high earners ($145,000+ FICA wages) must direct catch-up contributions to Roth 401(k) starting 2026 under SECURE 2.0 Section 603 — a major change for high-income savers.

For HSA holders, the IRS still limits investment options to what your HSA custodian offers — choose a custodian with low-fee index fund options like Fidelity, Lively, or HSA Bank. For penalty-free non-medical use, see our IRA early withdrawal calculator for comparison; HSA non-medical withdrawals before age 65 carry a 20% penalty, double the IRA's 10%.

Last updated April 2026. Sources: IRS Publication 969, irs.gov 2026 inflation adjustments, Fidelity Retiree Health Care.