Still working at 65 with employer coverage

The 20-employee rule (simplified)

If you (or your spouse) have group health coverage based on current employment:

• Employers with 20 or more employees: the group plan usually pays first and Medicare pays second. Many people in this situation delay Part B.
• Employers with fewer than 20 employees: Medicare usually pays first. Enrolling in Part B on time often matters more here.

Ask your benefits office for a written answer. Rules can differ for retiree plans, COBRA, and disability situations.

Special Enrollment Period (SEP)

If you delay Part B because of qualifying group coverage based on current employment, you can usually sign up:

• Any time while you are still covered by that group plan, or
• During the 8-month period that starts the month after employment ends or the group coverage ends, whichever is first.

Enrolling during this SEP generally avoids the Part B late penalty. Retiree coverage and COBRA usually do not give you the same Part B SEP — confirm before you delay.

Part D and creditable coverage

Drug coverage has its own late-enrollment rules. If your employer drug coverage is “creditable” (as good as Medicare’s), you can often delay Part D without a Part D penalty. Get that in writing from the plan each year.