Last Updated: August 12, 2026 Reading Time: 9 min

A handful of FEHB plans will deposit up to $2,000 a year into an account you keep forever, and most federal employees have never run the numbers. The HSA attached to FEHB high-deductible plans is the only triple-tax-advantaged account in the federal benefits stack, it comes with employer money through the premium pass-through, and it quietly beats the Roth TSP on tax treatment for medical spending. It also has a trap at 65 that catches feds every year.

How the Pass-Through Turns a Premium Into Savings

Every FEHB high-deductible plan routes part of the premium you and the government already pay into your HSA. It arrives monthly, it's yours immediately, and it doesn't depend on you contributing anything.

The verified 2026 figures for the biggest player: GEHA HDHP deposits $1,000 a year for self-only enrollment and $2,000 for family. OPM lists roughly a dozen more FEHB HDHPs with pass-throughs of their own, generally in the $800 to $2,400 range depending on plan and tier; the exact amount is on the first pages of each plan brochure. Postal employees have parallel options in PSHB, where GEHA's PSHB HDHP matches the $1,000/$2,000 deposits.

The pass-through counts against your IRS limit. A self-only GEHA HDHP enrollee can add $3,400 of their own money on top of the $1,000 deposit to reach the $4,400 cap.

The Triple Tax Advantage, Fed Edition

Money into an HSA through payroll skips federal income tax and, unlike TSP contributions, skips FICA too. Maxing the $4,400 self-only limit through payroll saves about $337 in Social Security and Medicare tax before the income-tax savings even start. Growth is untaxed. Withdrawals for qualified medical expenses are untaxed, at any age.

Compare the stack: traditional TSP is taxed on the way out, Roth TSP is taxed on the way in, and both pay FICA. The HSA pays tax at no point when spent on medical care. For the medical bills that virtually everyone eventually has, it is the best-treated dollar in the federal system.

The standard priority order for a fed with spare savings capacity: TSP up to the 5% match first (nothing beats a 100% match), then seriously consider maxing the HSA before adding unmatched TSP dollars.

The Worked Example: HDHP vs. a Standard Plan

The instinct that stops most people is "high deductible means I'll pay more." Run 2026 numbers for a healthy self-only GEHA enrollee choosing between GEHA Standard and GEHA HDHP:

  • The HDHP's premium is lower, and the plan deposits $1,000 into your HSA.
  • Net of premium savings and the pass-through, the HDHP enrollee comes out roughly $1,100 ahead in year one before any tax savings on their own contributions, and about $2,400 ahead for family enrollment.
  • The trade: a $1,700 minimum deductible (self-only) before most non-preventive care is covered, with a 2026 out-of-pocket maximum of $8,500 capping the downside.

A high-utilization year can flip the math, which is exactly the comparison our FEHB Calculator total-cost estimator is built for: it models premiums plus expected out-of-pocket costs by usage level, side by side.

The Medicare Trap at 65

This is the part that generates painful IRS letters.

Enrolling in any part of Medicare ends HSA eligibility. Contributions after enrollment are excess contributions with penalties attached. The nastier version: if you claim Social Security after 65, Medicare Part A enrollment is automatic and backdated up to six months. Contributions made during that lookback window retroactively become excess.

The rule of thumb for feds working past 65: stop HSA contributions six months before you plan to claim Social Security or enroll in Medicare. You can keep the account and spend it forever; you just can't add to it. Pair this with the Part B decision itself, which we cover in Medicare Part B for 2027: The Premium Projection.

Who Can't Play

  • TRICARE enrollees. TRICARE is disqualifying coverage, full stop. Military retirees carrying TRICARE alongside FEHB cannot contribute, whichever FEHB plan they pick.
  • General-purpose FSA holders. A regular health-care FSA (yours or your spouse's) disqualifies you. The limited-expense LEX FSA, which covers dental and vision only, is the compatible version FSAFEDS offers for exactly this reason.
  • VA care nuance. Care for a service-connected condition doesn't affect eligibility. Recent non-service-connected VA medical care can, for a rolling three-month window. Veterans using VA care should check this one carefully.

Set It Up During Open Season

Open Season (November 10 to December 8) is when you can move into an HDHP for 2027. Before then: compare your current plan against the HDHP options with the FEHB Calculator, check the pass-through amount in the brochure of any plan you're considering, and if you're within a few years of Medicare, sketch the contribution stop date now.

Calculate Your Plan Comparison

Use our free FEHB Calculator to compare HDHP premiums, government contributions, and estimated total annual costs against your current plan before Open Season locks your 2027 choice. Try it now →

Frequently Asked Questions

What are the 2026 HSA contribution limits?

$4,400 for self-only coverage, $8,750 for family, plus $1,000 catch-up at 55+. The plan's pass-through deposit counts against the limit.

How much does the GEHA HDHP pass-through pay?

$1,000 a year for self-only and $2,000 for family enrollment in 2026, deposited from premiums into your HSA automatically.

Is the HSA better than the TSP?

They serve different jobs. Nothing beats the TSP match, so capture that first. After the match, HSA dollars get strictly better tax treatment than unmatched TSP dollars for anyone who will ever have medical expenses.

Why do feds lose HSA eligibility at 65?

Medicare enrollment ends contributions, and claiming Social Security after 65 backdates Part A up to six months, retroactively disqualifying contributions in that window. Stop contributing six months ahead.

Can I have an FSA and an HSA?

Not a general-purpose FSA. The limited-expense (LEX) FSA for dental and vision is the compatible option, and FSAFEDS offers it specifically for HDHP enrollees.

Sources: IRS Rev. Proc. 2025-19 and IRS Publication 969 · OPM HSA guidance · GEHA 2026 HDHP plan brochure · IRS Notice 2004-50 (Medicare lookback) · FSAFEDS LEX FSA materials