Medicare is Health supplemental insurance offered by the federal government to most people who are 65 and older and to some younger people with disabilities. It has two parts: Hospital Insurance, called Medicare Part A, helps pay for hospital bills, Medical Insurance, called Medicare Part B, helps pay for doctor bills. Most people who are 65 and older, some younger people with disabilities and people with kidney failure can get Health supplemental insurance. 

You are automatically signed up for Medicare when you turn 65 if you are getting Social Security or Railroad Retirement payments. You'll receive a package of Medicare information, including your Medicare card, in the mail.
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You need to sign up for Medicare yourself if you do not get Social Security or Railroad Retirement payments. 

When you sign up for Health supplemental insurance, you will get Part A, which covers hospital bills. Most people do not have to pay a monthly cost (premium) for Part A. That is because they or their spouse paid Medicare taxes while they were working. 

Signing up for Health supplemental insurance Part B, which pays for doctor bills, is your choice. You will have to pay a monthly premium for Part B. You can sign up when you first go on Medicare, turn down the coverage, or wait to sign up at a later date. If you are working and already have group health insurance from your employer or your spouse's employer, you might not need Part B right away. However, you need to be aware that if you wait to sign up for Part B, the premium could go up by 10 percent for each year you could have had Part B. You will have to pay that extra cost as long as you remain on Medicare. You sign up for Medicare Part B while you are still working and covered by group health insurance, or You sign up for Medicare Part B within eight months after you are no longer covered by group health insurance. 

If you think you will meet these conditions and decide to wait, here's what you need to do: 

• If Medicare signs you up for the program, you will get Parts A and B. You will need to tell Medicare you don't want to keep Medicare Part B at this time. You will get a form to do this in the packet of Medicare information you receive in the mail.
• If you sign up for Medicare yourself by calling or visiting your local Social Security office, you need to tell Medicare you don't want Part B.
• If you don't meet these conditions, you will have to pay more for Medicare Part B when you do get it. You may want to talk to your employer's benefits manager about whether getting Part B when you first sign up for Medicare is right for you.
• If you are 65 or older, when you sign up for Part B, you have six months to buy any Health supplemental insurance (Medigap) policy you choose, regardless of your health. This is called your open enrollment period. You only have this period once in your life. After this six-month period, you may not be able to buy the Health supplemental insurance policy you want.
• If you are 65 or older, are working and have group health coverage from your or your spouse's employer, you can save your open enrollment period until you need it.