Read the Spanish version: Entendiendo Medicare
Medicare is a federal health insurance program for people age 65 or older, younger people with certain disabilities and people with end-stage renal disease. About 44 million people, which is approximately 15% of the U.S. population, have a Medicare plan. 

Most Medicare beneficiaries have “Original Medicare.” This is the traditional fee-for-service arrangement, which means you can go to any healthcare provider who accepts Medicare. 

Original Medicare includes two parts:

  • Part A covers hospital bills. Most people don’t have to pay a premium for Part A.
  • Part B covers medically necessary doctors visits, lab tests and supplies, such as wheelchairs and walkers and preventive care, such as flu shots. You pay a premium for Part B.
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You can add coverage for prescription medicine by purchasing a Medicare Prescription Drug Plan – called Part  D – from a private company approved by Medicare. Drug plans vary by cost and the drugs they cover.

To help pay costs original Medicare doesn’t cover, you can purchase supplemental insurance called Medigap. Medigap policies, which are sold by private insurers approved by Medicare, cover out-of-pocket expenses, such as copayments, co-insurance and deductibles.

Medicare handbook

View the “Medicare & You” handbook on Medicare's official website, or call the agency at (800) 633-4227 and ask for one.

The toll-free number is staffed by English- and Spanish-speaking customer service representatives.

Hearing-impaired individuals using a telephone device for the deaf can call (877) 486-2048.

Instead of choosing original Medicare, you can opt for a Medicare Advantage plan, also known as Part C. More than one-third of Medicare enrollees have a Medicare Advantage plan in 2017.

Medicare Advantage plans cover everything original Medicare covers. Most plans include drug coverage, and some cover additional services, such as vision and dental care. Medicare Advantage plans can have additional benefits, such as plans geared to people with particular health issues like diabetes. Private companies sell Medicare Advantage plans.

You can’t use Medigap with a Medicare Advantage Plan. In fact, it’s against the law for anyone to sell you a Medigap plan if you have Medicare Advantage, unless you’re switching back to original Medicare.

Which is better – original Medicare or a Medicare Advantage plan?

The answer of this question depends on your situation.

Generally, your choices are less restricted with Original Medicare than with most Medicare Advantage plans. With Original Medicare, you can go to any doctor, hospital or other healthcare provider who accepts Medicare.

Medicare Advantage offers multiple choices so you can find the plan that's right for you. These plans also have lower premiums than Original Medicare. However, Original Medicare has lower deductibles. 

Which plan is more popular? conducted a survey to find out. See the results

Who pays for Medicare?

Medicare is financed by federal taxes and administered by the Centers for Medicare & Medicaid Services. Beneficiaries pay premiums and out-of-pocket costs, including Medicare deductibles and copayments. People with Original Medicare can also get Medigap, which also has premiums and out-of-pocket costs. 

Beneficiaries must also pay for their own custodial care, most dental care, dentures, routine foot care and hearing aids.

Who is eligible for Medicare?

To be eligible, you or your spouse must have worked for at least 10 years in Medicare-covered employment, be age 65 or older, and be a citizen or permanent resident of the United States. A younger person with a disability or with chronic kidney disease also might qualify for Medicare.

Are there income limits?

There are no income limits to enroll in Medicare. Your salary may affect how much you pay, but it won't forbid you from getting Medicare. 

How do I enroll in Medicare?

Many people are enrolled in Medicare automatically. Enrollment is automatic if you are not yet age 65 and you're already receiving Social Security or Railroad Retirement benefits. If you're disabled, you will be automatically enrolled in both Part A and Part B of Medicare beginning with your 25th month of disability.

Most people have to enroll in Medicare one of two ways. You have an individual enrollment period, which begins three months before you turn age 65 (or right away if you require regular dialysis or a kidney transplant) and continues for seven months. Applying early can help you avoid a possible delay in the start of your Part B coverage. If you miss your individual enrollment, you will need to wait until the annual Medicare Open Enrollment period.

To apply for Medicare, contact any Social Security Administration office or fill out an application online on the Social Security website. (If you or your spouse worked for the railroad, contact the Railroad Retirement Board.) If you don't enroll during these 10 months, you'll have to wait until the three months beginning on Jan. 1, and your Part B coverage won't start until July. 

If you have questions about Medicare eligibility or enrollment, call Social Security's toll-free number, 1-800-772-1213 or visit the Social Security website.

You can't enroll in Medicare through your state's health insurance marketplaces, aka exchanges. The exchanges sell only individual and nongroup health insurance policies.

What happens if I wait to enroll?

Don't delay signing up for Medicare when you're eligible. If you wait 12 or more months to enroll, your premiums likely will be higher.

Even if you continue to work and have employer-sponsored health insurance after your 65th birthday, you should sign up for Part A of Medicare. Part A might help pay some of the healthcare costs not covered by your employer plan. Typically, the premium is free.

Talk to your benefits manager if you have employer-sponsored coverage to learn whether you should sign up for Part B. The answer will depend on whether your employer-sponsored coverage will be considered secondary coverage to Medicare Part B, or primary coverage. Primary coverage pays first, and secondary coverage pays the costs that the primary insurance doesn’t cover. If your employer-sponsored insurance is the secondary coverage, you might need to sign up for Part B. Otherwise, your insurance might pay little or nothing. Find out more about coordination of benefits

Keep in mind that under some circumstances, you'll have to pay an extra 10% per year penalty if you miss the Part B deadline and sign up later. Why would you get penalized for not taking Medicare? Younger seniors have less healthcare needs than older seniors. So, delaying Medicare until you're older means you haven't paid in premiums during those years and will have much higher healthcare needs when you're older. 

What is a Medicare HMO?

A Medicare health maintenance organization (HMO) is a type of Medicare Advantage plan. It provides all Medicare-covered services under Parts A and B and may provide additional benefits — such as prescription drug coverage — that aren't offered with traditional Medicare. Medicare HMO plans are sold by private companies and are available in most parts of the country. In most HMOs, you can go only to healthcare providers in the plan’s network, except in an emergency.

What is a Medicare PPO?

Like an HMO, a Medicare Advantage preferred provider organization (PPO) covers all the services that original Medicare Parts A and B covers. Some plans also include coverage for prescription drugs and other services, such as vision and dental care. You pay less out-of-pocket to see healthcare providers in the PPO network, but you still have some coverage to see providers outside the network. PPOs charge higher premiums than HMOs.

What are Medicare private fee-for-service plans?

These plans, offered by private health insurers, are hybrids of Medicare HMOs and original Medicare. Like original Medicare, there is no provider network; you can go to any doctor, hospital or clinic that accepts Medicare. However, the amount the plan pays for care may differ from what original Medicare pays. The plan might also cover services that original Medicare doesn’t cover.


Can I join more than one Medicare plan?

No, you can't join more than one Medicare health plan at the same time.

What if I want to leave a Medicare health plan?

You can change plans or switch to original Medicare during the annual open enrollment period, which runs each year from Oct. 15 to Dec. 7 for coverage starting Jan. 1 of the next year. You can also enroll in a Medigap supplementary plan during this period if you switch from a private Medicare health plan to original Medicare.

Where can I get help when changing plans?

If you're switching Medicare Advantage plans, you can join the new plan during one the annual open enrollment period (Oct. 15 to Dec 7 each year). You should be automatically disenrolled from your old plan when you new plan's coverage begins. If you are switching Original Medicare plans, you need to contact your current plan representative or call 1-800-MEDICARE (1-800-633-4227).

You can also contact your State Health Insurance Assistance Program (SHIP) for help.

Medicare also recently improved Medicare Plan Finder. This tool allows you to compare plans. 

Medicare financial help and benefits

There are several programs available to help low-income Medicare beneficiaries pay for some of their Medicare out-of-pocket expenses, such as premiums, deductibles or Medigap. For each of these programs the income requirements vary.

  • The Qualified Medicare Beneficiary (QMB) Program pays for your Medicare premiums, deductibles, and co-insurance.
  • The Specified Low Income Medicare Beneficiary (SLMB) Program pays for your Medicare Part B premium.
  • The Qualified Individual 1 (QI-1) Program pays for your Medicare Part B premium.
  • The Qualified Disabled and Working Individuals (QDWI) Program helps pay the Part A premium if you qualify.

Individuals who may be qualified for any of these programs can apply at their local Medicaid offices.