HSA Calculator 2026

The Health Savings Account is the only account that achieves all three tax breaks simultaneously: deductible going in, tax-free growth, tax-free withdrawal. Roth IRA gets two of three (no deduction). Traditional 401(k) gets two of three (taxable on withdrawal). HSA wins all three layers.

For someone in the 22% federal bracket who maxes a family HSA at $8,750/year for 30 years and invests it in S&P 500 (7% real return), the math works out to roughly $880K of tax-free retirement medical spending at age 65 — built from $263K of contributions and $617K of compound growth, with another $58K saved in taxes along the way (the contributions themselves saved 22% × $263K).

The catch: you must be enrolled in a qualified High-Deductible Health Plan (HDHP) to contribute. 2026 HDHP minimums are $1,650 self / $3,300 family deductible — meaningful out-of-pocket exposure for an unhealthy year. Many young, healthy workers find HDHP + HSA economically dominates traditional PPO coverage; older workers or those with chronic conditions may not.

The conventional use of an HSA is "save money for medical expenses you'll incur this year." That's fine, but it leaves enormous value on the table. The optimized approach: treat the HSA as a stealth retirement account.

Step 1: Max your contribution every year ($4,400 self / $8,750 family in 2026). Step 2: Invest aggressively — most providers offer S&P 500 index funds once you cross a $1K-$2K minimum. Step 3: Pay current medical expenses out of pocket from your regular budget, NOT from the HSA. Step 4: Save every medical receipt indefinitely. Step 5: Decades later, withdraw HSA funds to reimburse yourself for past medical expenses — tax-free, at any age, with no statute of limitations.

The math is staggering. A 30-year-old maxing a family HSA at $8,750/year and investing in stocks for 35 years compounds to ~$1.3M tax-free. Even after saving every medical receipt, that's a substantial supplemental retirement fund. After age 65, any non-medical withdrawal is taxed as ordinary income (no penalty) — making the HSA at minimum equivalent to a Traditional IRA, with the upside of tax-free use for medical (which retirees disproportionately incur).

Most of the population never executes this strategy — they treat the HSA as a glorified FSA, draining it annually for current expenses. The compound miss over 30 years is hundreds of thousands of dollars per family.

Three things shift at age 65: (1) the 20% early-withdrawal penalty for non-medical withdrawals goes away — non-medical withdrawals are now simply taxed as ordinary income (same as a Traditional 401(k)/IRA); (2) you become Medicare-eligible, and Medicare enrollment makes you HSA-ineligible for new contributions (you can still spend existing balance); (3) HSA dollars can pay Medicare Part B and Part D premiums tax-free — but NOT Medigap supplemental premiums.

Strategic timing: stop HSA contributions 6 months before claiming Social Security. Why? Because claiming SS automatically enrolls you in Medicare Part A retroactively up to 6 months. Any HSA contributions during that retroactive period become "excess contributions" subject to a 6% annual excise tax. Most retirees miss this and get a small surprise tax bill.

Also: HSA balances pass to a spouse tax-free if they're the named beneficiary (the account remains an HSA in the spouse's name). If a non-spouse inherits, the entire balance becomes taxable income to the beneficiary in the year of inheritance — significantly worse treatment than IRA inheritance, which has 10-year stretch rules. So name your spouse, and consider drawing down HSA assets before non-spouse inheritance becomes likely.