Turning 65? Here's how the Medicare process works.

Your Initial Enrollment Period

When you turn 65, you get a 7-month window to enroll in Medicare for the first time: the 3 months before your birthday month, your birthday month, and the 3 months after. If your birthday falls on the 1st of the month, your window starts one month earlier.

Part A and Part B

Part A helps cover hospital stays and is usually premium-free if you or your spouse paid Medicare payroll taxes for at least 40 quarters (about 10 years). Part B helps cover doctor visits, outpatient services and preventive care, and it carries a monthly premium.

If you're already receiving Social Security benefits when you turn 65, you'll generally be enrolled automatically. If not, you sign up through the Social Security Administration at ssa.gov.

If you're still working

If you have active employer group health coverage from an employer with 20 or more employees, you may be able to delay Part B without a penalty and enroll later. When that coverage ends, you'll have an 8-month Special Enrollment Period to sign up.

Avoiding late penalties

If you don't have qualifying coverage and miss your Initial Enrollment Period, you could face a lifetime late-enrollment penalty — typically 10% of the Part B premium for every 12-month period you were eligible but didn't sign up. Enrolling on time is the easiest way to avoid it.

The Medigap open enrollment window

Once your Part B is active, you have a 6-month Medigap Open Enrollment Period. During this window you can buy a Medicare Supplement (Medigap) policy with guaranteed issue — no medical underwriting required. This is generally the best time to apply.

What to gather before you talk to an agent

• A list of your doctors, specialists and pharmacies
• Your current medications and dosages
• Any employer, VA or TRICARE coverage you have
• Chronic conditions and care needs
• A rough monthly budget for premiums and care