Health care is one of the largest expenses for American households, and the tax code offers two main accounts to soften the blow: the health savings account and the flexible spending account. Comparing HSA vs FSA is a common open enrollment question because they sound similar and both use pre-tax dollars. In practice, they differ in eligibility, ownership, rollover rules, and long-term value.
How a health savings account works
A health savings account (HSA) is a tax-advantaged account you own, paired with a qualifying high-deductible health plan (HDHP). It offers what is often called a triple tax advantage under federal law:
- Contributions are tax deductible, or pre-tax if made through payroll, which also avoids Social Security and Medicare taxes.
- Earnings grow tax free.
- Withdrawals for qualified medical expenses are tax free.
Most states follow the federal treatment, but California and New Jersey tax HSA contributions and earnings at the state level.
HSA eligibility
To contribute to an HSA, you must be covered by an HSA-qualified HDHP, have no other disqualifying health coverage (such as a general-purpose FSA or Medicare), and not be claimed as a dependent on someone else’s tax return. The IRS sets minimum deductibles and maximum out-of-pocket limits for qualified HDHPs each year, along with annual contribution limits for self-only and family coverage. People 55 and older can contribute an additional $1,000 catch-up contribution.
Federal legislation enacted in 2025 expanded HSA eligibility in some situations, including making bronze and catastrophic marketplace plans HSA-compatible and allowing certain direct primary care arrangements, starting in 2026. Because these rules are new, check current IRS guidance and confirm with your plan whether it qualifies.
HSA ownership and investing
The HSA belongs to you, not your employer. Funds roll over year after year with no deadline, and the account stays with you if you change jobs or retire. Many HSA providers allow you to invest balances above a cash threshold in mutual funds or ETFs.
Some people treat the HSA as a stealth retirement account. They pay current medical bills out of pocket, save receipts, invest the HSA, and reimburse themselves years later. There is no IRS time limit for reimbursing a qualified expense incurred after the HSA was established, provided you keep records. After age 65, you can withdraw HSA funds for non-medical purposes without the 20 percent penalty, paying ordinary income tax, similar to a traditional IRA.
How a flexible spending account works
A health care flexible spending account (FSA) is an employer-sponsored account that lets you set aside pre-tax salary for medical expenses. The IRS sets an annual limit, adjusted for inflation. Unlike an HSA, you do not need a high-deductible plan to participate.
A distinctive feature of the health FSA is the uniform coverage rule: your full annual election is available on the first day of the plan year, even though you fund it through payroll deductions over the year. If you elect $2,000 and have a $2,000 surgery in January, the FSA can reimburse the full amount immediately.
The use-it-or-lose-it rule
The tradeoff is that unused FSA money is generally forfeited at the end of the plan year. Employers may soften this with one of two options, but not both:
- Carryover. Allows a limited amount, indexed annually by the IRS, to roll into the next year.
- Grace period. Gives you up to two and a half extra months to spend the prior year’s funds.
Because of this rule, FSA elections should be based on predictable expenses, such as regular prescriptions, planned dental work, glasses, or contacts.
Limited-purpose and dependent care FSAs
A limited-purpose FSA covers only dental and vision expenses and can be paired with an HSA. A dependent care FSA is a separate account for child care or adult day care so you can work. It is not for medical expenses and has its own limit, which federal legislation raised starting in 2026.
Comparing HSA vs FSA
| Feature | HSA | Health FSA |
|---|---|---|
| Requires HDHP | Yes | No |
| Who owns it | You | Employer plan |
| Rollover | Unlimited | Limited carryover or grace period, if offered |
| Portability | Stays with you | Usually ends with job |
| Investment options | Often available | No |
| Full balance available day one | No, only what is deposited | Yes |
What counts as a qualified medical expense
IRS Publication 502 describes deductible medical expenses, and HSA and FSA rules generally follow it. Common qualified expenses include doctor visits, hospital bills, prescription drugs, dental care, vision exams, glasses and contacts, hearing aids, mental health care, and medical equipment. The CARES Act of 2020 restored the ability to use these accounts for over-the-counter medicines without a prescription and added menstrual care products.
Generally excluded: cosmetic procedures, general health items such as vitamins unless recommended for a specific condition, and most insurance premiums. HSAs are an exception for some premiums, including COBRA, coverage while receiving unemployment, Medicare premiums after 65 (but not Medigap), and qualified long-term care insurance.
Choosing between plans at open enrollment
Many employers offer both a traditional PPO with an FSA and an HDHP with an HSA, sometimes with an employer HSA contribution. To decide:
- Estimate your expected medical spending. Include prescriptions, therapy visits, and planned procedures.
- Compare total cost. Add annual premiums to your expected out-of-pocket costs under each plan, then subtract any employer HSA contribution and your tax savings.
- Consider your cash cushion. An HDHP requires you to pay more before insurance kicks in. If you could not handle a large bill early in the year, the PPO with an FSA’s day-one balance may feel safer.
- Think long term. If you are healthy and can afford to fund the HSA without spending from it, the investment growth can become meaningful over decades.
Practical tips
- Keep digital copies of receipts and explanation of benefits statements.
- Use the HSA debit card carefully so that only qualified expenses are paid with it; non-qualified withdrawals before 65 face income tax and a 20 percent penalty.
- If you are approaching Medicare, stop HSA contributions in time. Enrolling in Part A can be retroactive up to six months, which can create excess contributions.
- Name a beneficiary on your HSA. A spouse who inherits it can treat it as their own; other beneficiaries generally must include the balance in income.
Common HSA and FSA mistakes
- Over-electing an FSA. Elections based on hoped-for expenses rather than planned ones lead to forfeited money. Start with recurring costs you are sure of.
- Leaving HSA money in cash forever. Many HSA providers default to a cash account. If you are saving for the long term, review the investment options and fees.
- Losing receipts. If the IRS asks about a withdrawal, you need to show that it paid for a qualified expense. A dedicated folder or app helps.
- Contributing after losing eligibility. If you switch from an HDHP to a non-qualifying plan mid-year, your HSA contribution limit is generally prorated by month, with special rules under the last-month rule.
- Ignoring employer money. Many employers seed HSAs or match contributions. That money is part of your compensation.
Transferring and consolidating HSAs
Because HSAs belong to you, workers who change jobs often end up with more than one account. You can move money from one HSA to another through a trustee-to-trustee transfer, which has no annual limit and is not reported as a distribution. A 60-day rollover is also allowed, but only once per 12-month period. Consolidating can reduce fees and make investing simpler, though you may want to keep the account linked to your current employer’s payroll contributions.
Related reading: How State Minimum Auto Insurance Requirements Actually Work in the US.
Frequently Asked Questions
Can I have both an HSA and an FSA?
Not a general-purpose health FSA. You can pair an HSA with a limited-purpose FSA or a dependent care FSA.
What happens to my FSA if I leave my job?
Coverage typically ends on your last day unless you elect COBRA for the FSA. Submit claims for eligible expenses incurred before your last day by the plan’s deadline.
Can my spouse’s expenses be paid from my HSA?
Yes, qualified expenses for your spouse and tax dependents can be paid from your HSA, even if they are not covered under your HDHP.
This article is for general informational purposes only and is not legal, medical, tax, or financial advice. Rules vary by state and change over time; confirm details with the relevant agency or a licensed professional.
