To be eligible for Medicare, individuals must generally be either 65 years old or older, or have a qualifying disability. Additionally, individuals with end-stage renal disease (ESRD) or amyotrophic lateral sclerosis (ALS) may also be eligible for Medicare. It's important to note that eligibility requirements can vary based on specific circumstances, so it's advisable to consult official Medicare resources or speak with a healthcare professional for personalized guidance on enrollment eligibility.