The answer
Do I need to sign up for Medicare if I have other insurance?
It depends on the kind of other insurance you have.
If you have active employer coverage through a job with 20 or more employees, where you or your spouse still work, you can usually delay Medicare without penalty and sign up later through a Special Enrollment Period. If your employer has fewer than 20 employees, Medicare often becomes the primary payer, so you typically need to enroll at 65 to avoid gaps. Retiree coverage, COBRA, and marketplace plans generally do not count as active employer coverage, so delaying Medicare with those can trigger a late penalty. The rules turn on whether the coverage is active and the employer's size. To check your specific situation, reach out to a licensed Goodsurance advisor at 1-888-301-8091 (TTY 711), Mon to Fri 8 am to 5 pm PT.