Who is eligible for Medicare:

Both U.S. citizens and qualified legal residents have to be one of the following:

1. Age 65 or older
2. Younger than 65 with a qualifying disability (you must be disabled for at least 2 years to be eligible for Medicare if under the age of 65)
3. Any age with a diagnosis of End-Stage Renal Disease (ESRD) or Amyotrophic Lateral Sclerosis (ALS, commonly known as Lou Gehrig’s Disease)
4. To qualify as a legal resident, you must have lived in the United States for at least 5 years in a row before applying for Medicare.

For Medicare Part A to be premium free according to Department of Health and Human Services:

• If you are age 65 or older and you or your spouse worked and paid Medicare taxes for at least 10 years.
• You are receiving retirement benefits from Social Security or the Railroad Retirement Board.
• You are eligible to receive Social Security or Railroad benefits, but you have not yet filed for them.
• You or your spouse had Medicare-covered government employment.

For more information on eligibility please see: Medicare.gov eligibility tool