HSA: The Triple Tax Advantage

2026 contribution limits

• Self-only coverage: $4,400
• Family coverage: $8,750
• Catch-up (age 55+): additional $1,000
• HDHP minimum deductible: $1,700 self-only, $3,400 family
• HDHP maximum out-of-pocket: $8,500 self-only, $17,000 family

Eligibility

To contribute to an HSA, you must:

• Be covered by a qualifying HSA-eligible High Deductible Health Plan (HDHP).
• Not be enrolled in Medicare.
• Not be claimed as a dependent on someone else's tax return.
• Not have other non-HDHP health coverage (with specific exceptions for dental, vision, disability, long-term care, and some FSAs).

Enrolling in Medicare ends HSA contribution eligibility. Many pre-Medicare planners max their HSA aggressively in their 50s and early 60s to build a tax-free medical-expense fund for later.

The optimal HSA strategy: pay cash, invest the HSA

Most people use their HSA the way they use an FSA — paying current medical bills out of the HSA balance. This works but wastes the compounding benefit.

The optimal strategy:

1. Contribute the maximum each year while HSA-eligible.
2. Invest the balance aggressively (many HSAs let you invest above a $1,000 floor).
3. Pay current medical bills from your checking account.
4. Keep receipts.
5. Reimburse yourself years or decades later — tax-free.

Why this works: HSA withdrawals for qualified medical expenses are tax-free in the year of the expense or any later year. There is no time limit. You can pay a $300 dental bill in 2026 with after-tax dollars, keep the receipt, and reimburse yourself in 2046 — after 20 years of tax-free compounding on that $300.

This effectively converts the HSA into an IRA with a bonus feature. Keep a folder (digital or paper) of qualified medical expense receipts; withdraw against them whenever you want tax-free cash.

Qualified medical expenses

The IRS publishes a long list (Publication 502). The main categories:

• Doctor visits, dentist, optometrist
• Prescriptions
• Medical equipment
• Long-term care insurance premiums (age-based limits)
• Medicare premiums (Parts B and D) after age 65
• Dental and vision
• Mental health care

Non-qualified withdrawals before age 65 incur a 20% penalty plus ordinary income tax. After 65, non-qualified withdrawals have no penalty — you just pay ordinary income tax, making the HSA function like a Traditional IRA. This is why HSAs are sometimes called "stealth IRAs."

HSA vs FSA (critical distinction)

Don't confuse an HSA with a Flexible Spending Account:

• HSA — Yours forever. Rolls over year to year. Portable across employers. Investable.
• FSA — Use-it-or-lose-it (with limited carryover). Tied to your employer. Not investable.

HSAs win on every metric if you're eligible.

When HSA isn't the right move

A few scenarios where HSA eligibility matters less:

• Frequent medical expenses that exceed HDHP deductible. An HDHP's high deductible can be costly for chronic conditions; sometimes a traditional PPO makes more sense despite losing HSA access.
• Pregnancy planning. First-year costs of childbirth often exceed an HDHP's deductible substantially.
• Low overall income. If you're in the 10% or 12% marginal bracket, the tax deduction value is smaller and other savings vehicles may compete.

HSA in retirement

After age 65:

• HSA can pay Medicare Part B and D premiums (but not supplemental insurance).
• Non-qualified withdrawals incur no penalty; taxed as ordinary income.
• HSA remains valuable through late retirement for covering end-of-life care costs, which are often substantial.

Planning estimates from Fidelity and others put lifetime out-of-pocket healthcare costs in retirement at $300,000+ for a couple. An HSA filled during working years is purpose-built for this liability.

How Horizons uses this

HSA accounts in Horizons are tagged with the triple tax treatment. Contributions reduce current-year tax, growth is tax-free in the forecast, and withdrawals for healthcare expenses are untaxed. The engine naturally routes healthcare expenses to the HSA first, preserving other accounts for non-medical retirement spending.