HSA vs. FSA: What's the Difference and Which Should You Use?

HSA: Health Savings Account

An HSA is a tax-advantaged savings account for healthcare expenses. To open one, you must be enrolled in a qualifying High-Deductible Health Plan (HDHP).

2026 contribution limits:

• Individual: $4,300
• Family: $8,550
• Catch-up (age 55+): Additional $1,000

The triple tax advantage:

1. Contributions are tax-deductible (or pre-tax if through payroll)
2. Growth is tax-free
3. Withdrawals for qualified medical expenses are tax-free

Key features:

• Funds roll over year to year — no "use it or lose it"
• You own the account — it stays with you if you change jobs
• After age 65, you can withdraw for any purpose (taxed as income, like a traditional IRA)
• Many HSAs allow you to invest funds in mutual funds once you reach a minimum balance

FSA: Flexible Spending Account

An FSA is an employer-sponsored account that lets you set aside pre-tax dollars for healthcare expenses. Unlike an HSA, you don't need an HDHP to use an FSA.

2026 contribution limit: $3,300 (employer may add more)

Key features:

• Use it or lose it: Most FSA funds must be used by year-end (some plans allow a $640 rollover or 2.5-month grace period)
• Employer-owned — you lose it if you leave your job
• Full annual election available on day one
• No investment option

Types of FSAs:

• Healthcare FSA: Medical, dental, vision expenses
• Dependent Care FSA: Childcare, elder care expenses (separate $5,000 limit)
• Limited Purpose FSA: Dental and vision only — can be used alongside an HSA

Key Differences Side by Side

• HDHP required: HSA (yes) vs. FSA (no)
• Rollover: HSA (unlimited) vs. FSA (limited or none)
• Portability: HSA (yours forever) vs. FSA (employer-owned)
• Investment option: HSA (yes) vs. FSA (no)
• 2026 limit: HSA $4,300/$8,550 vs. FSA $3,300
• Available day one: FSA (yes, full amount) vs. HSA (only what you've contributed)

The HSA Investment Strategy

The most powerful HSA strategy: contribute the maximum, pay current medical expenses out of pocket, and invest your HSA funds for long-term growth. Save your receipts.

After years of growth, you can reimburse yourself for those old medical expenses tax-free — there's no time limit on reimbursements as long as the expense occurred after you opened the HSA. This effectively turns your HSA into a tax-free investment account.

A maxed-out HSA invested in index funds for 20 years could grow to $200,000+ — all available tax-free for medical expenses (or taxed as income after 65 for any purpose).

Which Should You Choose?

• Choose HSA if: You're enrolled in an HDHP, you're healthy, and you want to maximize tax advantages and long-term savings
• Choose FSA if: You're not on an HDHP, you have predictable medical expenses, or you want to use the full annual amount on day one
• Use both if: You have an HSA-eligible HDHP and your employer offers a Limited Purpose FSA (dental/vision only) — you can contribute to both