FEHB vs. Medicare Advantage at Open Season: Three Doors, One Locks

Last Updated: September 27, 2026 Reading Time: 10 min

The FEHB vs. Medicare Advantage question has three answers, not two, and the cheapest one locks behind you. A retired federal employee on Medicare can keep FEHB as is, keep FEHB and add the Medicare Advantage option some carriers bundle inside it, or suspend FEHB for a private Medicare Advantage plan. Two enrollment windows for 2027 decide it: Medicare's runs October 15 to December 7, 2026, and FEHB Open Season runs November 9 to December 14, 2026. This piece prices all three doors at 2026 rates, by income tier, and explains which one you can walk back through.

Quick Answers: FEHB vs. Medicare Advantage

Can I drop FEHB for a Medicare Advantage plan?

Do not drop it. Suspend it. Federal regulation lets an annuitant suspend FEHB to enroll in a Medicare Advantage plan, and suspension preserves your right to come back. Cancelling does not: OPM states that canceling FEHB coverage as an annuitant is permanent. File form RI 79-9 with proof of your Medicare Advantage enrollment; a Medicare card alone is not proof.

Can I get FEHB back after suspending it for Medicare Advantage?

Yes. You can re-enroll during the annual Federal Benefits Open Season or, per OPM, if you have a qualifying life event. If you lose the Medicare Advantage coverage involuntarily, for example the plan leaves your county, you get a window from 31 days before to 60 days after the loss to re-enroll in any available FEHB plan. What you cannot do is quit the plan voluntarily in March and be back on FEHB in April.

Does FEHB pay my Medicare Part B premium?

Some plans give part of it back, and the mechanism differs. Aetna Advantage's Medicare Advantage option reduces the Part B premium you pay Social Security by $100 a month per Medicare-primary member, credited in the Social Security check. GEHA's High Option reimburses annuitants on Parts A and B up to $1,000 a year, and FEP Blue Basic reimburses up to $800 a year through a Medicare Reimbursement Account you must claim. Most FEHB plans give back nothing.

What is the difference between a Medicare Advantage plan inside FEHB and one I buy myself?

Inside FEHB, you keep paying your FEHB premium and the carrier layers a group Medicare Advantage plan on top; OPM confirms you will not need to suspend FEHB coverage. Outside FEHB, you suspend your enrollment to stop paying for coverage you are not using, and that suspension puts your return trip on a calendar. Inside costs more each month and is reversible; outside is cheaper and sticky.

How much does each path cost in 2026?

For a couple both 66 on Self Plus One at Aetna Advantage premiums: $8,383 a year on FEHB plus Part B with no Part B credit, $5,983 with the inside-FEHB Medicare Advantage option, and $4,870 if they suspend FEHB for a $0-premium outside plan. A single retiree: $4,032, $2,832 and $2,435. FedTools 2026 analysis at standard-tier Part B.

Does a higher income change which option is best?

In this 2026 Aetna example it changes the bill, not the ranking: IRMAA lands on Part B identically on every path, so the premium you pay to keep your FEHB enrollment alive is $33.10 a month single and $92.82 a month for a couple at every income tier: standard, IRMAA tier 1 at $284.10 a month, and tier 2 at $405.80 a month alike.

What happens to my spouse if I suspend FEHB for Medicare Advantage?

Suspension applies to the enrollment, not to one person, and the regulation denies the enrollee and covered family members any temporary extension of coverage or right to convert to an individual policy. If your spouse is 61 and not Medicare-eligible, suspending drops them to nothing with no bridge.

Why do I have to decide before FEHB Open Season ends?

Two calendars, two closing dates. The Medicare Advantage election period for 2027 runs October 15 to December 7, 2026. FEHB Open Season runs November 9 to December 14, 2026. If your plan depends on an outside Medicare Advantage plan, that election has to land by December 7 if you are using the annual election period, a week before the FEHB window shuts (an initial or special enrollment period, if you qualify for one, runs on its own dates).

Is there a catch to the inside-FEHB Medicare Advantage plans?

Three. The Medicare Advantage layer is a separate CMS contract that depends on annual renewal, so it can change while your FEHB plan continues. Some plans treat your enrollment as agreement to be placed in their Medicare Advantage plan; on Aetna Advantage, if that enrollment does not complete, the $2,000 deductible is not waived and you pay 30% coinsurance on most services. And the plan adjudicates under Medicare rules, so prior authorization and networks become part of your care.

Can I keep FEHB and join a Medicare Advantage plan from a different company?

Yes, and it is usually the worst of the three. Your FEHB plan will still coordinate benefits; Aetna Advantage's 2026 brochure says it waives none of its copayments, coinsurance or deductible when you join another carrier's Medicare Advantage plan (check your own plan's brochure), and OPM contributes nothing toward the Medicare Advantage premium. For Aetna Advantage, the brochure says these FEHB copayments, coinsurance and deductible are not waived; check your own plan and any outside-plan premium.

The Three Doors, Priced at 2026 Rates

The scenario is stated in full so you can reproduce it. A federal annuitant who turns 66 in 2026, on premium-free Part A and on Part B, choosing among three paths. Self Only means one person on Part B. Self Plus One means a spouse who is also 66, also on Part B, and also opted into the plan's Medicare Advantage option. The FEHB premium is the 2026 Aetna Advantage annuitant share printed in the plan's own brochure ($133.10 a month Self Only, $292.82 Self Plus One), held constant across paths A and B so the table isolates what the Medicare Advantage option changes. Part B is the 2026 standard premium of $202.90 a month, or $284.10 at IRMAA tier 1 (income above $109,000 single or $218,000 joint) or $405.80 at tier 2 (above $137,000 or $274,000).

FedTools 2026 analysis of FEHB-plus-Part-B premium subtotals only (drug-plan premiums, any Part D IRMAA and all cost-sharing are excluded on every path). Inputs: Aetna Advantage 2026 brochure (RI 73-906) rate table, p. 118, and the $100-a-month Part B reduction on p. 38; 2026 Part B premium and IRMAA table from the Federal Register notice of November 19, 2025. Annual figures are monthly figures times 12, with no rounding at any step. The credit in path B is two individual $1,200 reductions for a couple, not a family benefit. Excluded from every path: Medicare Advantage cost-sharing, the $283 Part B deductible, dental, vision, Part D plan premiums, Part D IRMAA and drug cost-sharing; a person suspending FEHB (path C) must check the outside plan's drug coverage separately. The usual "FEHB or Medicare Advantage" framing misses two things the table shows.

First, the price of keeping your FEHB enrollment alive is $397.20 a year single and $1,113.84 a year for a couple, and it does not move when IRMAA does. At the standard tier a couple pays $5,983 on path B against $4,870 on path C. At tier 2 the same couple pays $10,853 against $9,739. The gap is $1,113.84 in both cases because IRMAA falls on Part B on every path equally. Income changes the size of the bill. Within this 2026 premium-only example it does not change the ranking; rerun it on the 2027 rates before you elect.

Second, path B beats path A by exactly the credit, at every tier, while also zeroing the deductible and most cost-sharing on the Aetna plan. For many retirees the cheapest insured option is FEHB and Medicare Advantage at once, not one or the other.

Your own plan's premium is the number to substitute. The FEHB Calculator prices the annuitant share for any plan and enrollment tier so you can rebuild the table with your plan in row A.

Door One: Keep FEHB, Skip Medicare Advantage

This is where most retirees sit, and it is the most expensive door in the table when the plan pays nothing toward Part B. It is also the simplest: no forms, no calendars, no networks beyond what your FEHB plan already has. For an annuitant Medicare pays first and the FEHB plan pays second, and that secondary payment wipes out most of the cost-sharing.

Whether Part B itself is worth $202.90 a month on top of FEHB is a separate question, and this piece does not re-argue it. The FEHB and Medicare Part B guide covers that decision, and the income-bracket math post covers what IRMAA does to it.

Door Two: Keep FEHB and Add Its Medicare Advantage Option

Several FEHB carriers bundle a group Medicare Advantage plan inside the FEHB plan for members who have Parts A and B. OPM's Medicare page says it plainly: "If you elect a Medicare Advantage plan accessed through your FEHB plan, you will not need to suspend FEHB coverage." You must have both Part A and Part B to elect it.

Aetna Advantage is the worked example because its 2026 brochure prints every number. The plan's Medicare Advantage option reduces the Part B premium the member pays Social Security by $100 a month, credited in the Social Security check rather than claimed as a reimbursement, and the member must opt in. The option's benefit table shows a $0 deductible, $0 primary care and specialist cost-sharing, and a $2,000 per-person out-of-pocket maximum that applies to the drug benefit.

Three catches, all from the same brochure. The Medicare Advantage layer "is a Medicare contract separate from the FEHB Aetna Advantage Plan and depends on contract renewal with CMS," so it can change or vanish while your FEHB plan continues. Choosing the plan at 65 or older with Medicare primary is an agreement to be enrolled in its Medicare Advantage plan, and the brochure warns that if that enrollment is not completed, "your benefits will be significantly impacted, i.e. $2,000 deductible not waived and you will pay 30% coinsurance on most services." And enrollment is limited to people who live or work in the service area; Postal annuitants are no longer eligible unless they hold temporary continuation of coverage.

Other carriers run the same structure with different credits. GEHA's 2026 brochure reimburses High Option annuitants on Parts A and B up to $1,000 a year for Part B premiums. FEP Blue is not a Medicare Advantage plan, but its Basic Option reimburses members on Parts A and B up to $800 a year through a Medicare Reimbursement Account that the member has to claim. Several other carriers offer group Medicare Advantage options with their own credits; the only reliable figure is the one in that plan's 2026 brochure.

Door Three: Suspend FEHB for a Private Medicare Advantage Plan

The regulation is 5 CFR 890.304(d)(2): an annuitant or survivor annuitant "may suspend enrollment in FEHB for the purpose of enrolling in a Medicare-sponsored plan" under the Medicare Advantage statute. Four rules govern the door.

Suspend, never cancel. OPM's page is blunt: "Canceling FEHB coverage as an annuitant is permanent. In other words, you will not have the option to reenroll in FEHB if you cancel your FEHB coverage." Suspension is the reversible version.

It is not automatic. Joining a Medicare Advantage plan does nothing to your FEHB enrollment by itself. You file form RI 79-9 with the retirement system, with proof of the Medicare Advantage enrollment. OPM's annuitant FAQ adds that "a copy of your Medicare card alone will not allow you to suspend your FEHB enrollment."

The filing window is 31 days before through 31 days after the Medicare Advantage effective date. File inside it and the suspension takes effect the day before the new plan starts, with no gap and no overlap. File late and the suspension takes effect at the start of the first pay period after the retirement system receives the paperwork, which means paying both premiums in the meantime. A late filing costs you overlapping premiums, not the right to suspend.

There is a route back, on a calendar. Under 5 CFR 890.306(f)(1)(ii), an annuitant who suspended for a Medicare Advantage plan "may reenroll." OPM's page names two doors: "You can re-enroll during the annual Federal Benefits Open Season or if you have a QLE." If you lose the Medicare Advantage coverage involuntarily, because the plan leaves your county or ends its contract, 890.306(h)(1) lets you re-enroll in any available FEHB plan at any time from 31 days before to 60 days after the loss. Quit the plan voluntarily in March, though, and the Aetna brochure's description of the general rule applies: you wait for the next Open Season unless you lost coverage involuntarily or moved out of the service area.

What door three costs is the FEHB re-entry right, priced above at $33.10 a month single and $92.82 for a couple, plus whatever the private plan's cost-sharing, prior authorization and network turn out to be worth to you. The dollar table assumes a $0-premium plan is offered in your county. Many counties have several; some have none.

The Spouse Trap

Suspension operates on the enrollment, not on one person. 5 CFR 890.304(d)(3) says the suspended enrollee "and covered family members are not entitled to the temporary extension of coverage for conversion or to convert to an individual contract for health benefits."

Consider a 61-year-old spouse. The retiree is on Medicare and can join a Medicare Advantage plan. The spouse is not Medicare-eligible for four years. Suspending the Self Plus One enrollment drops the spouse to no coverage, with no 31-day extension and no conversion policy, and the spouse cannot rejoin FEHB until the annuitant re-enrolls at Open Season or on a qualifying life event.

One more block: an annuitant under a court or administrative order to cover a child cannot cancel or suspend the enrollment while the order stands, unless the annuitant documents other coverage for the child.

Two Deadlines, a Week Apart

The Medicare Advantage annual election period for 2027 runs October 15 through December 7, 2026, under 42 CFR 422.62. FEHB Open Season for 2027 runs November 9 through December 14, 2026, under the formula in 5 CFR 890.301: the Monday of the second full workweek in November through the Monday of the second full workweek in December.

If your 2027 plan depends on a private Medicare Advantage plan, the Medicare election has to land by December 7 under the annual election period (initial and special election periods have their own dates). The FEHB suspension paperwork then has its own 31-day window around the January 1 effective date. If your plan is door two, the FEHB election by December 14 is what matters, and the plan's own Medicare Advantage opt-in follows.

As of September 27, the cited 2027 rates were not published; check the releases before making your election. As of September 27, OPM's premium index still tops out at plan year 2026; 2026 rates landed on October 9, 2025, so expect early to mid October. CMS has not published the 2027 Medicare Advantage plan list or premiums either. The 2027 Part B premium is projected at $209.50 in the 2026 Trustees Report, a projection covered in the Medicare Part B 2027 projection post, and CMS announces the official figure in November. The dollar levels in the tables above will move. The gaps and ranking must be recalculated using 2027 premiums, credits and plan terms.

One last rule for anyone tempted to drop FEHB entirely rather than suspend it: FEHB drug coverage is creditable. Go 63 days or more without drug coverage at least as good as Medicare's and your Part D premium rises at least 1% for every month you went without, permanently.

Price Your Own Plan

Use the free FEHB Calculator to pull your plan's 2026 annuitant premium by enrollment tier and rebuild the three-door table with your numbers in row A. Try it now. If your income sits near $109,000 single or $218,000 joint, the IRMAA Cliff Calculator shows how close you are to the next Part B tier. Postal annuitants, who are excluded from the Aetna plan above, should start with the PSHB Part B Calculator.

Related Resources

• FEHB and Medicare Part B Guide 2026: Whether Part B is worth adding to FEHB at all.
• FEHB vs. Medicare: The Income-Bracket Math: What IRMAA does to the Part B decision.
• FEHB and Medicare Part D: Why FEHB drug coverage counts as creditable.
• PSHB and the Medicare Part B Trap: The Postal version of this decision.
• FEHB 2027 Premiums: Rumors vs. Confirmed: Where the 2027 rates stand.
• TRICARE vs. FEHB Calculator: For military retirees weighing a third system.

Sources

• 5 CFR 890.304, Termination of enrollment (suspension at (d))
• 5 CFR 890.306, Opportunities for annuitants and survivor annuitants to enroll or change enrollment
• 5 CFR 890.301, Opportunities for employees to enroll or change enrollment (Open Season formula at (f))
• 42 CFR 422.62, Election of coverage under an MA plan
• 5 U.S.C. 8905, Election of coverage
• OPM, Medicare and FEHB and OPM annuitant FEHB FAQ
• OPM, FEHB premiums index (no 2027 rates as of September 27, 2026)
• Aetna Advantage 2026 brochure, RI 73-906; Blue Cross and Blue Shield Service Benefit Plan 2026 brochure, RI 71-005; GEHA 2026 brochure, RI 71-006
• CMS, Medicare Part B premium and IRMAA amounts for 2026, Federal Register, November 19, 2025
• KFF, Medicare Advantage in 2026: Enrollment Update and Key Trends