Enroll in Medicare through Social Security

Medicare is the federal health insurance program for people age 65+ and certain younger people with disabilities. The Social Security Administration handles Medicare enrollment, even though Medicare itself is run by a separate agency (CMS). Knowing when to enroll is critical — late enrollment carries lifetime penalties.

The four parts of Medicare

• Part A (Hospital Insurance) — covers inpatient hospital, skilled nursing, hospice. Free for most people who paid Medicare taxes for 10+ years.
• Part B (Medical Insurance) — covers doctor visits, outpatient care, preventive services. Has a monthly premium ($185 base in 2026, higher for higher incomes).
• Part C (Medicare Advantage) — bundles A and B (and usually D) into a private plan. Optional alternative.
• Part D (Prescription Drug Coverage) — covers prescription drugs. Optional, separate premium.

When to enroll

Initial Enrollment Period (IEP)

Your seven-month window around your 65th birthday:

• Three months before your birth month
• Your birth month
• Three months after your birth month

Enrolling before your birth month means coverage starts on the first day of your birth month. Enrolling later means coverage starts later.

Are you auto-enrolled?

Yes, if you're already receiving Social Security retirement benefits before age 65. You'll automatically be enrolled in Parts A and B starting the month you turn 65, and your Medicare card arrives in the mail about three months before your birthday.

If you're not already on Social Security, you must actively enroll. The SSA does not contact you.

If you miss your IEP

You can enroll during the General Enrollment Period (January 1 to March 31 each year), with coverage starting the month after enrollment. But you may face a permanent late enrollment penalty for Part B (10% of the premium for each full 12 months you delayed) and Part D (1% of the national base premium per month delayed).

Special Enrollment Periods (SEP)

If you have employer health coverage based on current employment (yours or your spouse's) when you turn 65, you can delay Medicare enrollment without penalty. You then have an 8-month Special Enrollment Period after that coverage ends to enroll in Medicare without penalty.

How to enroll

Three ways:

1. Online at ssa.gov — fastest, takes about 10 minutes.
2. By phone at 1-800-772-1213.
3. In person at your local SSA office (find one in our state directory).

Whichever method, you're enrolling in Original Medicare (Parts A and B). Medicare Advantage (Part C) and Part D enrollment is done separately, through Medicare.gov or directly with private insurers.

What if you don't want Part B right away?

Part B has a monthly premium, so some people delay it. This is only safe if you have qualifying coverage from current employment. Delaying Part B without qualifying coverage results in lifetime penalties.

Part A is free for most people, so there's rarely a reason to refuse it.

Frequently asked questions

How much does Medicare cost?

Part A is free for most. Part B base premium is $185/month in 2026 (higher for higher incomes via IRMAA). Part D varies by plan. Out-of-pocket costs include deductibles, copays, and coinsurance.

Can I have Medicare and employer insurance?

Yes. One typically pays first ("primary"), the other second ("secondary"), depending on employer size and your situation. Coordinating the two correctly is worth a phone consultation.

What about Medigap (Medicare Supplement)?

Medigap is private insurance that helps pay Medicare's out-of-pocket costs. Best time to buy is during your six-month Medigap Open Enrollment Period starting the month you're 65 and enrolled in Part B. You can be turned down outside that window.