How to Use the HSA Contribution Calculator
- Contribution & Tax Savings tab. Select your HDHP coverage type (self-only or family), enter your age, and input how much you and your employer have contributed to your HSA so far this year. Enter the number of months you’ve been enrolled in an HDHP (use 12 if you’re enrolled all year). Add your estimated combined tax rate to see the dollar value of your remaining contribution room. The calculator shows your pro-rated limit, how much room you have left, and the estimated tax savings on that remaining space.
- Long-Term Growth Projection tab. Enter your current HSA balance, your annual contribution amount (or leave blank to use the 2026 IRS maximum), an expected annual return rate, and how many years you’re projecting. The calculator projects your balance at key ages, shows total tax-free investment growth, and calculates the taxable equivalent value of your HSA at the end of the period.
- HSA vs. FSA Comparison tab. Enter your income, expected medical expenses, tax rate, and years until retirement. The comparison shows both accounts side by side — annual limits, tax savings, investment growth, and a long-term balance projection — alongside a full feature comparison table.
How HSAs Work
The Triple Tax Advantage
The HSA is the only account in the U.S. tax code with three separate tax benefits. Contributions are tax-deductible (or pre-tax through payroll, which also saves FICA taxes). The balance grows tax-free — invested in mutual funds, ETFs, or index funds, with no capital gains tax along the way. And withdrawals for qualified medical expenses are 100% tax-free. A traditional 401(k) has only the first two benefits. A Roth IRA has the last two. The HSA has all three — but only for medical expenses, and only if you’re enrolled in a qualifying High Deductible Health Plan.
2026 HSA Contribution Limits
| Coverage Type | 2026 Limit | Age 55+ Catch-Up | Maximum (55+) |
|---|---|---|---|
| Self-Only HDHP | $4,300 | +$1,000 | $5,300 |
| Family HDHP | $8,550 | +$1,000 | $9,550 |
These limits include both your contributions and any employer contributions. If your employer puts $600 into your HSA, your personal contribution limit is reduced by $600. Married couples where both spouses are 55 or older and each has a self-only HDHP can each open separate HSAs and each make the catch-up contribution — $5,300 × 2 = $10,600 combined.
The HSA as a Retirement Account
Here’s what most people miss: after age 65, HSA withdrawals for non-medical expenses are taxed exactly like traditional IRA or 401(k) withdrawals — ordinary income tax, no penalty. That means an HSA is essentially a second IRA for anyone who doesn’t need the funds for medical expenses. If you can afford to pay medical costs out-of-pocket and leave the HSA untouched, the full balance compounds tax-free for decades. A 35-year-old who maxes a family HSA every year and invests at 6% could accumulate over $800,000 by age 65 — entirely tax-free for medical use, or taxable like an IRA for any other purpose.
HDHP Requirements for 2026
| Requirement | Self-Only | Family |
|---|---|---|
| Minimum Annual Deductible | $1,650 | $3,300 |
| Maximum Out-of-Pocket | $8,300 | $16,600 |
HSA vs. 401(k): Which to Fund First?
Financial planners often recommend this priority order: contribute enough to your 401(k) to capture the full employer match (free money), then max your HSA (triple tax advantage), then return to maxing your 401(k) or Roth IRA. The HSA beats additional 401(k) contributions above the match because of the triple tax benefit — a dollar in an HSA is worth more than a dollar in a traditional 401(k) when used for qualified medical expenses, because the 401(k) withdrawal is taxed and the HSA withdrawal is not.
Frequently Asked Questions
What is a High Deductible Health Plan (HDHP) and do I have one?
An HDHP is a health insurance plan with a higher deductible than traditional plans. For 2026, the IRS requires a minimum deductible of $1,650 for self-only coverage or $3,300 for family coverage. Check your Summary of Benefits and Coverage or your insurance card — if your plan is labeled as “HDHP” or “HSA-compatible,” you qualify. Some employers clearly mark HSA-eligible plans during open enrollment. If your deductible is $1,000 for a self-only plan, you don’t qualify, even if your employer offers an HSA alongside it.
What qualifies as a tax-free HSA withdrawal?
The IRS defines qualified medical expenses broadly — doctor visits, prescriptions, dental care, vision care, mental health services, medical equipment, and thousands of other items. Since 2020, over-the-counter medications and feminine hygiene products also qualify without a prescription. Cosmetic procedures, gym memberships, and most insurance premiums do not qualify. One exception: Medicare premiums and long-term care insurance premiums are qualified HSA expenses after age 65, making the HSA especially valuable in retirement.
Can I invest my HSA balance?
Yes — most HSA providers allow you to invest your balance in mutual funds or ETFs once your balance exceeds a certain threshold (often $1,000–$2,000). Not all HSA administrators offer investment options or offer good ones, so it’s worth comparing providers. Fidelity, Lively, and HealthEquity are frequently cited as having strong investment menus. If your employer’s HSA administrator has poor investment options, you can often transfer funds to a better provider annually — similar to an IRA rollover.
What happens to my HSA if I change jobs or lose my HDHP coverage?
Your HSA balance is yours permanently — it doesn’t disappear when you change jobs or lose HDHP coverage. You can continue to use the funds for qualified medical expenses at any time, regardless of what health plan you’re currently on. However, you cannot make new contributions to the HSA once you’re no longer enrolled in a qualifying HDHP. Think of it as the account freezing in terms of new contributions but remaining fully accessible for withdrawals.
What is the last-month rule and should I use it?
The last-month rule allows you to contribute the full annual HSA limit in a year where you were only enrolled in an HDHP for part of the year — as long as you were enrolled on December 1. However, it comes with a catch: you must remain enrolled in an HDHP for the entire following year (the “testing period”). If you fail to do so, the excess contribution becomes taxable and subject to a 10% penalty. Unless you’re confident you’ll stay on an HDHP the following year, the safer approach is to pro-rate your contribution based on months enrolled.
Can I contribute to both an HSA and an FSA?
Generally, no — you cannot contribute to a standard Healthcare FSA and an HSA simultaneously. However, you can pair an HSA with a Limited Purpose FSA (LPFSA), which covers only vision and dental expenses. This combination lets you use the LPFSA for predictable vision and dental costs while preserving the full HSA for medical expenses and long-term investment growth. Some plans also offer a Post-Deductible FSA that activates after you’ve met your HDHP deductible.
💡 Tips for Getting the Most from Your HSA
- Invest your balance as soon as possible. Cash sitting in an HSA earns little or no interest. Once your balance exceeds the investment threshold (typically $1,000–$2,000), move it into a low-cost index fund. The tax-free compounding is the entire point of the account for long-term users.
- Pay medical bills out-of-pocket and let the HSA grow. There’s no deadline for reimbursing yourself from your HSA. Keep your medical receipts, pay the bill from your checking account, and reimburse yourself years later — after your invested HSA balance has grown. This effectively turns your HSA into a tax-free investment account while still capturing the medical expense reimbursement eventually.
- Contribute via payroll if possible. HSA contributions made through payroll deduction avoid FICA taxes (Social Security and Medicare) — a 7.65% savings that you don’t get from making contributions directly to your HSA outside of payroll. For someone maxing a family HSA at $8,550, that’s over $650 in additional FICA savings.
- Front-load contributions early in the year. The sooner your money is in the HSA and invested, the longer it compounds tax-free. If cash flow allows, contributing the maximum in January rather than spreading it out gives you an extra 11 months of tax-free growth on the early contributions.
- Use your HSA for Medicare premiums in retirement. After age 65, HSA funds can pay Medicare Part B, Part D, and Medicare Advantage premiums tax-free — an expense that can easily run $3,000–$6,000 per year in retirement. This makes an HSA one of the most targeted savings vehicles for a known, large retirement expense.
- Don’t leave your HSA with your old employer’s administrator. When you change jobs, you can roll your HSA to a provider with better investment options and lower fees. An annual HSA rollover to a provider like Fidelity (which has no HSA fees and strong fund options) can meaningfully improve long-term growth.