Medicare 2026

Still Working at 65? How Employer Coverage Affects When You Buy Medigap

If you're turning 65 and still working — or your spouse is, and you're on their plan — you may hear two pieces of advice that sound contradictory. One says, "Sign up for Medicare on time or face penalties." The other says, "You can keep your job-based coverage and delay Part B." Both can be true, depending on your situation. But there's a wrinkle many people don't learn about until it's too late: the timing of your Medigap Open Enrollment Period is tied to Part B, and it does not repeat.

Here's what that means in practice, and what to think about before you make a move.

The Medigap window most people don't realize they're using

Federal law gives every person one 6-month Medigap Open Enrollment Period. It begins the first month you are both 65 or older and enrolled in Part B. During those six months, an insurer cannot refuse to sell you any Medigap policy it offers, cannot use medical underwriting to deny you, and cannot charge you more because of pre-existing conditions.

After it ends, it does not come back. Outside this window (and outside a few guaranteed-issue situations), insurers in most states can ask health questions and decide whether to sell you a policy and at what price.

That rule creates a trap for people still working at 65. If you sign up for Part B while you also have employer coverage, your 6-month Medigap window starts anyway. It can quietly run out before you ever actually need a Medigap policy — which is typically when you leave the employer plan and move to Original Medicare.

Why CMS suggests many workers wait on Part B

If you or your spouse has group health coverage from current employment, CMS notes that benefits based on current employment often provide coverage similar to Part B, and employer coverage often provides coverage similar to Medigap. For that reason, many people in this situation choose to delay Part B until the job-based coverage ends.

There is an important exception. If the employer has fewer than 20 employees, the job-based plan might not pay for services unless you also have Part A and Part B. In small-employer situations, Medicare generally pays first, and skipping Part B can leave you with large bills. Ask the employer's benefits administrator in writing how the plan coordinates with Medicare before you decide.

The 8-month Special Enrollment Period for Part B

When group coverage based on current employment ends, you can sign up for Part B without a late-enrollment penalty during an 8-month Special Enrollment Period. That window ends 8 months after you or your spouse stop working, or after the job-based coverage ends — whichever happens first.

One detail trips people up: the 8 months start when you stop working, even if you elect COBRA. COBRA is not treated as current-employment coverage for this purpose. If you ride COBRA for a year and then try to pick up Part B, you can miss the window and face a lifetime late-enrollment penalty. Plan the transition to Part B around your last day of active employment, not around when COBRA runs out.

The guaranteed-issue right when employer coverage ends

Here's the piece that reconnects Part B to Medigap. If you have Original Medicare plus an employer group health plan (including retiree or COBRA coverage) or union coverage that pays after Medicare, and that plan is ending, you have a federal guaranteed-issue right to buy Medigap Plan A, B, C, D, F or G from an insurer in your state. Plans C and F are available only to people who were eligible for Medicare before January 1, 2020; people new to Medicare on or after that date have the right to buy Plan D or G instead.

You must apply no more than 63 days after the latest of: the date the coverage ends, the date on a notice that it is ending, or the date on a claim denial — if a denial is the only way you learn it ended. Keep those letters. The 63-day clock is strict.

A quick word on Medicare Advantage versus Original Medicare + Medigap

When you do leave employer coverage, you'll face a bigger choice: stay with Original Medicare (often paired with a Medigap policy and a stand-alone Part D plan) or enroll in a Medicare Advantage plan. Each path has trade-offs. Original Medicare lets you see any provider nationwide that accepts Medicare, and a Medigap policy can make out-of-pocket costs more predictable, but you pay a separate Medigap premium. Medicare Advantage plans typically use networks and prior authorization and may bundle extras, with cost-sharing that varies by service. Neither is "better" in the abstract — it depends on your health, providers, travel, and budget.

A few program-level numbers for context

For Part D, the out-of-pocket cap is $2,100 in 2026 and $2,400 in 2027. The maximum allowed Part D deductible in 2027 is $700, and the Part D base beneficiary premium used in the late-enrollment penalty calculation is $41.33 for 2027. Annual Enrollment for 2027 coverage runs October 15 – December 7, 2026. Social Security announced a 3.6% COLA for benefits payable beginning January 2027.

The 2027 Part B standard premium and deductible, and the 2027 IRMAA income brackets, have not yet been announced; CMS typically releases them in the fall.

If you have Medicaid or Extra Help

Since 2025, people with Medicaid or Extra Help have a monthly Special Enrollment Period to move to Original Medicare with a stand-alone Part D plan, or to switch stand-alone Part D plans. Full-benefit dual-eligible people can also join an integrated D-SNP in any month.

Where to go next

For official rules and personal help, use Medicare.gov or call 1-800-MEDICARE (1-800-633-4227), TTY 1-877-486-2048. Before you enroll in Part B, confirm with your employer how your plan coordinates with Medicare, and mark your calendar for the 8-month Special Enrollment Period and the 63-day Medigap guaranteed-issue window once that coverage ends.