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Medicare Versus Your Existing Insurance

When you should enroll in Medicare depends on your current coverage

Mature women working on a laptop in a kitchen

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En español | You may think that because you already have health insurance you don’t have to sign up for Medicare when you reach 65.

That’s not always the case.

If you are still working and have good health insurance through your employer — or your spouse’s — you may not need to enroll in Medicare yet.

But here’s the catch: It all comes down to where you work. If your company has 20 or more employees, you can delay enrolling in Medicare Part B without facing 10 percent higher Part B premiums for the rest of your life. But if you work for a company with fewer than 20 employees, you usually must sign up during what’s called your initial enrollment period, or face that 10 percent penalty. That sign-up period begins three months before and ends three months after the month of your 65th birthday.

If you get your current coverage through the Affordable Care Act (ACA) individual marketplace, a retiree health plan, COBRA or the military’s TRICARE for Life program, you also must sign up for Medicare Parts A and B during the initial enrollment period to avoid permanent penalties.