It's important to check the specific eligibility criteria of the health insurance plan you're interested in, as they can vary based on the plan type, insurer, and location.

• Age: Individuals turning 65 are eligible for Medicare. Those under 65 might qualify if they have certain disabilities or conditions like end-stage renal disease (ESRD) or amyotrophic lateral sclerosis (ALS).
• Citizenship or Residency: Applicants must be either U.S. citizens or legal residents who have lived in the country for at least five continuous years.
• Social Security Contributions: Many individuals become eligible based on their work history and having paid into Social Security for a required number of quarters.
• Automatic Enrollment: People receiving Social Security benefits are often automatically enrolled in Medicare Parts A and B when they turn 65.
• Enrollment Periods: There are specific enrollment periods, including the Initial Enrollment Period (when you first become eligible), General Enrollment Period, and Special Enrollment Periods triggered by qualifying events.
• Coverage Through Employer: Some individuals might delay enrolling in Medicare if they have health coverage through an employer or a spouse's employer.
• Medicaid Qualification: Eligibility for Medicaid in certain states can automatically qualify individuals for Medicare.