Medicare is a government health insurance program for people 65 and over, including some younger people with certain disabilities and illnesses.

When you turn 65, Medicare Parts A and B are available from the U.S. Government.

Medicare coverage includes 4 plans:

1. Medicare Part A (hospital coverage)

Part A helps pay for inpatient hospital stays or skilled nursing facility stays after a covered hospital stay. It also helps pay for some home health care and hospice care.

Medicare works the same way throughout the U.S.A. with any provider that accepts Medicare patients.

2. Medicare Part B (medical insurance)

Part B helps pay for services like doctor visits, lab test and some diagnostic screenings not covered by Part A hospital insurance. Various medical equipment and supplies are also covered.

Dental, vision, hearing and prescription drug benefits are not included.

3. Medicare Part C (Medicare Advantage Plan)

Medicare Advantage (Part C) plans are Medicare-approved, but offered by private insurers. They combine hospital costs, doctor visits, outpatient care, and often Part D prescriptions drug coverage, into one plan.

Some plans may offer vision, dental, and hearing and/or health programs, at an extra cost. These plans often require you to pay co-pays. The doctors and hospitals you go to are usually part of a network. You may also need a referral to see a specialist if you choose a Medicare Advantage Part C.

4. Medicare Part D (prescription drug coverage)

If you have Medicare Parts A and B, this plan can be purchased separately to help cover prescription drug cost. These plans are offered by Medicare-approved private insurers-costs and covered drugs vary from plan to plan.Part D works with a Medicare supplement (MediGap) insurance plan, or on its own. You can also get Part D benefits through some Part C plans.

Medicare Supplement Plans (also called MediGap policies) are private insurance plans that cover any additional costs that Medicare (Parts A and B) don't cover.

MediGap policies don't replace Medicare Parts A and B. Rather, they supplement the cost of expenses like deductibles, coinsurance, and copayments that Medicare doesn't cover. 

It's important to remember that MediGap policies and Medicare Advantage Plans (Medicare Part C) can't work together.

It's against the law for anyone to sell you a MediGap policy when you already have a Medicare Advantage Plan—unless you're planning to switch back to Medicare Parts A and B.

To answer that question there are 2 questions you'll need to consider regarding your exact age:

Are you turning age 65?

If you meet the following eligibility requirements, you can enroll in Medicare as early as three months before your 65th birthday month:

You’re a U.S. citizen or permanent resident for at least five consecutive years.

You can get hospital coverage (Medicare Part A) with no premiums if you the meet the requirements above, and:

1. You already get retirement benefits from Social Security or the Railroad Retirement Board
2. You are eligible to get Social Security or Railroad benefits but have not yet filed for them
3. You or your spouse had Medicare-covered government employment for at least 10 years

Are you under 65?

If you meet the following eligibility requirements, you can enroll in Medicare as early as three months before your 65th birthday month:

1. You are a U.S. citizen or permanent resident for at least five consecutive years, and
2. You have a disability or End-Stage Renal Disease and meet certain requirements

You can get hospital coverage (Medicare Part A) with no premiums if you meet the requirements above, and:

1. You have received Social Security or Railroad Retirement Board disability benefits for 24 months
2. You have End-Stage Renal Disease and /or meet certain requirements