Most Americans are familiar with Medicare, which was designed to provide coverage for people 65 years old or older. However, Medicare also covers a few special populations:
People with Lou Gehrig’s disease (ALS) are eligible when they receive Supplemental Security Income disability.
Disabled individuals who have received disability benefits from Social Security for at least 24 months are eligible for Medicare.
People with end-stage renal disease are eligible for Medicare if they have worked long enough to receive benefits under Social Security, the Railroad Retirement Board, or as a Medicare-qualified government employee. However, people with end-stage renal disease receive Medicare benefits only during specific treatment and/or recovery periods. For example, Medicare coverage begins after the third full month of hemodialysis treatment and ends 12 months after dialysis is complete. Medicare coverage begins in the first month of a kidney transplant and ends 36 months after the transplant.
Supplemental Security Income is available for disabled adults and low-income children. The Social Security Administration developed a 5-minute survey to help consumers discover if they are eligible. 
How do consumers enroll in Medicare? Consumers who receive Social Security checks are automatically enrolled. Consumers with Lou Gehrig’s disease are automatically enrolled as soon as they receive Supplemental Security Income disability benefits, as are individuals receiving Social Security disability benefits for 2 years.
All other eligible consumers must sign up for Medicare. Consumers with end-stage renal disease must contact Social Security Administration to enroll. Individuals 65 years old or older must sign up for Medicare by filling out an online application or appearing in person at a Social Security office. Consumers can sign up for Medicare as early as 3 months before turning 65 years old. If consumers don’t enroll 3 months before or after they turn 65, another general enrollment period starts January 1 and ends March 31.
What documents should consumers enroll? Consumers will need to present these documents to enroll in Medicare: birth certificate, proof of U.S. citizenship or documented immigrant status, copy of U.S. military service papers for those who served in the military, and copy of their W-2 form and/or self-employment tax return.
When signing up for Medicare, consumers can choose from a few options. All consumers can receive traditional Medicare, which includes Parts A and B.
Part A (hospital insurance): Part A includes inpatient hospital care, skilled nursing facility care, and hospice or home health care.
Part B (insurance for doctor’s visits, medical equipment, and medical assistance): Part B includes outpatient care, home health care, durable medical equipment (e.g., oxygen and wheelchairs), and some preventive care (e.g., depression and alcohol misuse screenings, mammograms, cancer screenings, cardiovascular disease screenings, certain immunizations, and type 2 diabetes screenings). Beneficiaries must pay an additional premium for Part B.
In addition, consumers can enroll in a prescription drug coverage plan by purchasing additional private health insurance.
Consumers can find an online application on the Social Security website. They can also call the toll-free service line at 1-800-772-1213. 
Part D (prescription drugs): Part D is an optional prescription drug benefit for Medicare beneficiaries. Although Part D is optional, there is a penalty if you sign up late.
Consumers may also purchase a Medicare Advantage Plan, or Part C, administered by a private insurance company. It’s important to note that the enrollment period for a Medicare Advantage plan is different. Open Enrollment for Part C begins October 15 and ends December 7.
Part C (Medicare Advantage): Medicare Advantage plans include Part A and Part B and typically include Part D. They can also have programs targeted at persons with special health needs. The ACA bans Medicare Advantage plans from increasing copays and deductibles on certain services.