People who turn 65 are eligible for Medicare, the federal health insurance program that provides coverage for older adults, but it doesn’t always mean you’ll be automatically signed up. Here’s what you need to know:

How do I know if I am automatically enrolled?

If you’re already collecting Social Security benefits, you’re automatically enrolled into Medicare parts A and B and will receive your Medicare insurance card and information about your benefits in the mail.

Part A covers in-patient hospital stays and skilled nursing and is free. Part B covers doctor’s visits, outpatient services, medical equipment and a number of other services and comes with a monthly premium of $185.

If you’re automatically enrolled in Medicare Part B, you will get a bill for your monthly premium. If you don’t pay it, the service will end after 90 days.

If you’re not yet collecting Social Security, you will need to sign up for Medicare. Since retirement age is 67 to receive full Social Security benefits, many people aren’t signed up at 65, though you can start receiving Social Security at a reduced amount as early as 62.

If I’m not automatically enrolled, how can I sign up?

Go to www.ssa.gov/benefits/medicare and select “Sign up for Medicare.” Or, call 800-633-4227. Although there’s no firm deadline, Medicare recommends applying three months before you turn 65.

What information do I need to sign up?

You will need your Social Security number, birth date and city where you were born, as well as start and end dates for your current health plan.

What about Medicare’s prescription drug plan?

Medicare Part D is a plan that covers prescription drugs, lowering out-of-pocket costs for many medications. While premiums vary depending on the plan, the average cost is about $50 monthly.

To learn more about enrolling, go to www.medicare.gov/health-drug-plans/part-d. or call 800-633-4227.

What if I want more insurance than what Medicare offers?

You may want more coverage than Medicare plans offer. The private market sells supplemental coverage, often called “Medigap” plans.

Many groups offer these plans, including AARP, Humana, Blue Cross, Mutual of Omaha, Cigna and others. Contact private insurance carriers directly for more information.

Can I reduce my Medicare costs?

Yes, depending on your income and assets. For a single person 65 and older with an income of less than $1,305, you can dual enroll in Medicaid, also called MaineCare in the state, and Medicare. For those enrolled in both programs, Medicaid will pay Medicare premiums and copays and more services will be available.

If you earn between $1,305 and $3,261 per month, you can enroll in the Medicare Savings Programs, which pays for premiums and, if your income is less than $2,413, will also pick up copay costs.

For more information, go to www.medicare.gov/basics/costs/help/medicare-savings-programs.