HSA Growth Calculator
A Health Savings Account is uniquely powerful when used as a long-term investment vehicle rather than a short-term spending account. By paying qualified medical expenses out-of-pocket and leaving your HSA contributions invested, the account compounds tax-free over time, producing a substantial balance available for healthcare costs in retirement or for general retirement spending after age 65. The IRS-permitted annual contribution limits make the HSA a significant supplemental retirement vehicle. This calculator projects your HSA balance over your chosen time horizon, accounting for your current balance, annual contributions, expected investment return, and any medical expenses you choose to reimburse from the HSA each year. Enter $0 for annual withdrawals to model the "invest and hold" strategy.
HSA growth formula
Each year: Balance = (Balance + Annual Contribution - Annual Withdrawals) x (1 + Return Rate)
Total Contributions = Initial Balance + Annual Contribution x Years
Tax-Free Growth = Final Balance - Total Contributions + Total Withdrawals
All growth is tax-free as long as funds are used for qualified medical expenses (or after age 65 for any purpose).
2025 HSA contribution limits (IRS)
- Self-only HDHP coverage: $4,300 per year.
- Family HDHP coverage: $8,550 per year.
- Age 55 or older catch-up contribution: additional $1,000 per year.
- Employer contributions count toward the annual limit.
- Unused balances carry forward with no "use it or lose it" rule, unlike FSAs.
HSA growth: frequently asked questions
What is the triple tax advantage of an HSA?
HSAs offer three tax benefits: (1) contributions are tax-deductible or pre-tax through payroll, reducing your taxable income; (2) investment growth inside the HSA is tax-free; and (3) withdrawals for qualified medical expenses are tax-free. This makes the HSA the most tax-advantaged account available to eligible Americans.
Who qualifies to contribute to an HSA?
You must be enrolled in a qualifying High-Deductible Health Plan (HDHP), not enrolled in Medicare, not claimed as a dependent on someone else's return, and not have other disqualifying health coverage. For 2025, HSA contribution limits are $4,300 (self-only) and $8,550 (family), with a $1,000 catch-up for those 55 and older.
Should I invest my HSA balance?
If you can afford to pay routine medical costs out of pocket, investing your HSA balance allows the money to compound tax-free over decades. Many HSA providers let you invest in mutual funds or ETFs once your balance exceeds a minimum threshold (often $1,000 or $2,000). The investment potential dramatically exceeds the savings account alternative.
What happens to HSA funds after age 65?
After age 65 you can withdraw HSA funds for any purpose without penalty (though non-medical withdrawals are taxed as ordinary income, similar to a traditional IRA). For qualified medical expenses including Medicare premiums and out-of-pocket costs, withdrawals remain completely tax-free at any age.
Can I use old medical receipts to reimburse myself from an HSA?
Yes. There is no time limit on reimbursements for eligible medical expenses incurred after your HSA was established. You can pay expenses out of pocket now, keep the receipts, let the HSA grow for decades, then reimburse yourself tax-free at any future date. This strategy maximises the investment compounding benefit.
Official sources
- IRS Publication 969: Health Savings Accounts and Other Tax-Favored Health Plans.
- IRS Revenue Procedure 2024-25: 2025 HSA Contribution Limits.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.