What Is Medicare? 

A Complete Guide to Medicare, Turning 65, Enrollment, Social Security, and Employer Coverage

Medicare can feel overwhelming when you first become eligible. You may hear terms such as Part A, Part B, Part C, Part D, Medicare Advantage, Original Medicare, Medigap, Initial Enrollment Period, Special Enrollment Period, and creditable coverage—sometimes all in the same conversation.

Fortunately, Medicare becomes much easier to understand once you break it into a few basic decisions.

At its core, Medicare is the federal health insurance program primarily for people age 65 and older. Certain people under age 65 may also qualify because of a disability, End-Stage Renal Disease (ESRD), or ALS.

For most people approaching Medicare, there are two major steps:

Your correct enrollment timing can depend on whether you are still working, whether your spouse is working, the type of employer coverage you have, the size of the employer, whether you contribute to a Health Savings Account, and whether you already receive Social Security benefits.