How to sign up for Medicare: the 7-month window, the penalty and job coverage

The date you sign up decides when coverage starts

Medicare coverage always starts on the first day of a month. Which month depends on when you sign up. If you get premium-free Part A, it starts the month you turn 65. If your birthday is on the first of the month, it starts the month before. For Part B, sign up before your birthday month and coverage starts the month you turn 65. Sign up in that month or in the 3 months after, and it starts the month after you sign up.

Waiting past your first window can leave a gap. Then you can only sign up from January 1 to March 31, and coverage starts the month after. The Part B penalty adds 10 percent to your premium for each full 12 months you could have had Part B but did not. You usually pay it for as long as you have Part B.

Answers to the questions from the first page

Why do some people get Medicare on their own? Some people are enrolled on their own because they already get Social Security or railroad retirement benefits. If those benefits start at least 4 months before you turn 65, you get Part A and Part B on your own. Your card arrives about 3 months before coverage starts. People under 65 with a disability are enrolled after 24 months of disability benefits. People with ALS are enrolled the month their disability benefits start. In Puerto Rico, you get Part A on your own but must sign up for Part B.

How do the sign-up window and the penalty work? Everyone else signs up during the Initial Enrollment Period. It lasts 7 months. It starts 3 months before the month you turn 65 and ends 3 months after it. If you or your spouse still work and have health coverage from that job, a Special Enrollment Period may let you wait.

Where do you sign up for Medicare? Social Security takes the sign-ups for Part A and Part B, online, by phone or at a local office. People who worked for a railroad, or whose spouse did, go to the Railroad Retirement Board. This site does not take applications.

How to sign up for Medicare step by step

The steps are the same in every state. Give the same answers on every form.

• Check if you are already enrolled. If you get Social Security or railroad retirement benefits, look for the welcome package. You may not need to do anything.
• Mark your 7-month window. Count 3 months before your birthday month and 3 months after it. Social Security suggests you contact it about 3 months before you turn 65.
• Have your details ready. You will need your Social Security number and the city, state and country where you were born. You will also need the start and end dates of any group health plan you have now or had after 65.
• Sign up online if you can. Medicare calls the online sign-up at Social Security the easiest and fastest way. You will create a my Social Security account first.
• If you have Part A and want only Part B, you can sign up online or use form CMS-40B during a sign-up period. Mail or fax it to your local Social Security office.

Your welcome package with your Medicare card comes about 2 weeks after you sign up.

What to do if you still work at 65

If you or your spouse still work and have a group health plan through that job, you may delay Part B. You can sign up any time while you have that coverage. You also have 8 months after the job or the coverage ends, whichever comes first. Then you usually pay no late penalty.

• If the employer has fewer than 20 employees, ask the employer first. That plan may not pay unless you have both Part A and Part B.
• COBRA and retiree coverage do not count as coverage from current work.
• When you sign up, send form CMS-L564. Your employer fills out Section B. If it cannot, fill it out as best you can and add proof, such as pay stubs that show health premiums.
• If you have a Health Savings Account, stop putting money in at least 6 months before you sign up. Premium-free Part A can start up to 6 months back.

The next page shows where to reach Social Security and who else can help.