Let's start with a basic understanding of Original Medicare.

In general terms, Original Medicare is a federally funded health insurance plan for people who are retired or have long-term disabilities.

To be eligible for Original Medicare coverage, you must meet at least one of these criteria:

You are age 65 or older

You are under age 65 and disabled for 24 consecutive months

You are of any age and are being treated for permanent kidney failure, or what is known as End-Stage Renal Disease.

Assuming you meet at least one of these criteria, you are eligible for Original Medicare if you or your spouse worked for at least 10 years in Medicare-covered employment and you are a citizen or permanent resident of the United States.

You may have heard Original Medicare described in "parts." The different parts of Original Medicare refer to the different types of health care services that are covered. For example, Medicare Part A pays for inpatient hospital costs, while Medicare Part B covers your outpatient doctor and medical services.

New prescription drug coverage is known as Medicare Part D.

Like private or employer-paid health insurance, Original Medicare requires payment of premiums. The premium for Medicare part A was pre-paid by your taxes while you were working.

Your premium for Medicare part B starts when you enroll in Medicare and requires you to pay a monthly fee directly to Social Security.