Many physicians continue practicing well beyond age 65. If you're one of them, deciding whether to remain on your practice's group health plan or to enroll in Medicare may seem straightforward—but the right decision often depends on your practice's size.
In some cases, delaying Medicare is the right decision. In others, waiting could lead to coverage gaps, unpaid claims, permanent late-enrollment penalties, and fewer Medicare Supplement options. Understanding how practice size affects Medicare enrollment can help you avoid costly mistakes.
Practice Size Matters
If your practice has more than 20 employees and your health coverage is through your employer or your spouse's employer, you may be able to continue that coverage and delay enrolling in Medicare without penalty while you're still working. Once your employment ends and you no longer have qualifying group coverage, you'll generally have a Special Enrollment Period to enroll in Medicare Parts A and B and avoid lifetime late-enrollment penalties. At that time, many physicians also chose to enroll in a Medicare Supplement plan and a Medicare Part D Prescription Drug Plan.
If your practice has fewer than 20 employees, Medicare generally becomes your primary health insurance when you become eligible at age 65. Remaining on your practice's group health plan doesn't necessarily mean you can delay enrolling in Medicare. To help avoid potential penalties, you'll typically need to enroll in Medicare Parts A and B during your Initial Enrollment Period, which begins three months before your 65th birthday, includes your birthday month, and ends three months afterward.
If you're covered by your practice's health plan, check with your insurance carrier to understand how your coverage will work after you enroll in Medicare. In some cases, your employer coverage may remain in effect as secondary coverage. Depending on your situation, transitioning to Medicare, a Medicare Supplement plan, and a Part D Prescription Drug Plan may also be worth considering.

Understand Your Medicare Enrollment Timeline
Regardless of practice size, understanding Medicare's enrollment deadlines is essential. Missing the right enrollment window could result in coverage gaps, unpaid claims, and permanent late-enrollment penalties.
After enrolling in Medicare Parts A and B, you may also want to consider a Medicare Supplement (also called Medigap) plan and a Medicare Part D Prescription Drug Plan. Medicare Supplement insurance helps pay many of the out-of-pocket costs that Original Medicare doesn't cover. The best time to enroll is during your one-time, six-month Medigap Open Enrollment Period, which begins when you're age 65 or older and enrolled in Medicare Part B.
This is your guaranteed opportunity to enroll in the Medicare Supplement plan you want without medical underwriting. Once this enrollment window closes, your guaranteed acceptance generally ends. After that, obtaining Medicare Supplement coverage may require answering health questions, completing medical underwriting, or could result in denial based on your health.
It's also important to confirm whether your current prescription drug coverage is considered creditable. Delaying Medicare Part D without other qualified prescription drug coverage could result in a permanent late-enrollment penalty.
Review Your Options Before You Decide
Medicare combined with a Medicare Supplement plan and a Medicare Part D Prescription Drug Plan may provide lower overall costs and fewer out-of-pocket expenses than remaining on your employer-sponsored group health plan. This may be especially true for physicians who don't have dependents covered under their employer-sponsored plan. Even if you're subject to an Income-Related Monthly Adjustment Amount (IRMAA), Medicare combined with a Medicare Supplement and Part D plan may still result in lower overall costs.
Reviewing your enrollment timeline and coverage options before making a decision can help you avoid unnecessary penalties, preserve your Medicare Supplement options, and choose the coverage that best fits your needs.
Key Medicare Enrollment Reminders
- If your practice has fewer than 20 employees, don't assume your group health plan allows you to delay enrolling in Medicare.
- Enroll in Medicare Part B at the appropriate time to help avoid permanent late-enrollment penalties.
- Confirm your prescription drug coverage is creditable before delaying Medicare Part D.
- Take advantage of your six-month Medigap Open Enrollment Period to preserve guaranteed access to Medicare Supplement coverage.
- Review your Medicare options with TMA Insurance Trust before making enrollment decisions.
TMA Insurance Trust advisors provide no-cost guidance to help physicians understand their Medicare enrollment timeline, compare Medicare Supplement and Part D plans from multiple carriers, evaluate how Medicare works with their current coverage, and make informed decisions based on their individual situation. Call 800-880-8181, Monday through Friday, 8:00 AM to 5:00 PM CST, to discuss your options and get answers to your questions.


