What Is an HSA? The Complete Guide to Health Savings Accounts

The Health Savings Account is the most tax-efficient savings vehicle the IRS allows. Contributions reduce your taxable income today, growth is tax-free, and qualified withdrawals are tax-free — a triple exemption unavailable in any other account. If you are eligible for an HSA and not using one strategically, you are leaving significant money on the table every year.

HSA vs. FSA vs. HRA: Key Differences

Three account types help employees pay for medical expenses pre-tax, but they work very differently. Understanding the distinctions before open enrollment determines whether you choose the optimal account for your situation.

The HSA's portability and investment capability make it categorically superior when you are enrolled in an HDHP. An FSA is a secondary option when HDHP coverage is unavailable or suboptimal for your health needs. You cannot have both a general-purpose Health FSA and an HSA simultaneously.

HDHP Eligibility: 2025 Thresholds

To contribute to an HSA, you must be enrolled in an IRS-qualified High Deductible Health Plan. For 2025, the IRS defines an HDHP as a plan with:

• Minimum annual deductible: $1,650 for self-only coverage; $3,300 for family coverage
• Maximum out-of-pocket limit: $8,300 for self-only; $16,600 for family

Additional eligibility rules: You cannot be enrolled in Medicare. You cannot be claimed as a dependent on someone else's return. You cannot have any other non-HDHP health coverage (with limited exceptions for specific dental, vision, disability, accident, and preventive care plans). These rules apply on the first day of each month — mid-year enrollment or changes require a prorated contribution calculation.

HSA Contribution Limits and the Catch-Up

HSA limits are adjusted for inflation annually. For 2024 and 2025:

• 2024 self-only: $4,150  |  2024 family: $8,300
• 2025 self-only: $4,300  |  2025 family: $8,550
• Catch-up (age 55+): Additional $1,000 per year per eligible spouse

Employer contributions to your HSA count toward these limits. If your employer deposits $1,000 into your HSA, your personal contribution limit is reduced by $1,000. You have until Tax Day (April 15) to make prior-year HSA contributions, even if you have already filed — just designate the contribution year correctly with your HSA provider.

The Triple Tax Advantage Explained

No other account type in the U.S. tax code offers all three of these simultaneously:

• Tax deduction on contributions: Contributions made directly to your HSA are deductible on Form 8889 regardless of whether you itemize. Payroll contributions avoid both income tax and FICA (7.65%) — an above-the-line deduction and FICA savings that a traditional IRA cannot match.
• Tax-free growth: All earnings — interest, dividends, and investment gains — accumulate tax-free inside the HSA. Unlike a taxable brokerage account, there are no annual tax events on growth.
• Tax-free qualified withdrawals: Withdrawals used for IRS-qualified medical expenses are completely tax-free at any age. Qualified expenses include most out-of-pocket medical costs: deductibles, copays, prescriptions, dental, vision, mental health therapy, and hearing aids.

The Best HSA Provider: Fidelity Wins

Your employer's default HSA provider is often mediocre. You can transfer your HSA balance to any provider once per year, and many people do not know this. Fidelity's HSA is the clear top choice for investors:

• No minimum balance to invest: Dollar one can go into index funds. Most providers require $2,000 to $3,000 in cash before investing.
• Zero-expense-ratio options: FZROX (total market) and FZILX (international) carry 0.00% expense ratios — the lowest available anywhere.
• No monthly maintenance fees: Many employer-assigned HSA custodians charge $3 to $5 per month, eroding balances for people with small accounts.
• Full investment flexibility: Access to thousands of ETFs and mutual funds, including Vanguard and iShares options.

If your employer's payroll HSA contribution goes to a different provider, consider making personal contributions directly to Fidelity's HSA and doing an annual trustee-to-trustee transfer of the employer HSA balance.

The Receipt Reimbursement Strategy

Most people use their HSA debit card to pay every medical bill — spending down the account immediately. This is the least powerful use of an HSA. The superior strategy is:

1. Pay every qualified medical expense out of pocket.
2. Save the receipt (digitally — a photo in a dedicated folder works).
3. Let the HSA balance invest and compound tax-free for years.
4. Reimburse yourself from the HSA at any time — there is no deadline.

The IRS does not require you to reimburse in the same year the expense was incurred. A $200 dental bill from 2025, paid out of pocket, can be reimbursed from your HSA in 2030 or 2035 after the invested funds have grown substantially. Ten years of $4,000+ annual contributions invested in index funds can grow to $70,000 $90,000 to available for tax-free withdrawal whenever you present those receipts.

HSA Rules at Age 65 and Dental/Vision/Mental Health

At age 65, HSA rules change materially. Non-qualified withdrawals no longer carry the 20% penalty — they are simply taxed as ordinary income, identical to a traditional IRA. Qualified medical withdrawals remain completely tax-free. This means the HSA effectively becomes a stealth IRA at 65, with the added benefit that healthcare spending (a major expense in retirement) is tax-free.

Commonly overlooked qualified expenses: dental cleanings and fillings, eyeglasses and contact lenses, LASIK eye surgery, orthodontia, hearing aids and batteries, mental health therapy and psychiatry, and medically necessary personal care items. Over-the-counter medications and menstrual care products became HSA-qualified in 2020. Gym memberships and cosmetic procedures generally do not qualify without a physician's Letter of Medical Necessity documenting treatment of a specific diagnosed condition.

Frequently Asked Questions