Coverage for Seniors: Medicare provides health insurance coverage for individuals aged 65 and older who are eligible for Social Security benefits or the Railroad Retirement Board benefits. Most people become eligible for Medicare when they turn 65, although some may qualify earlier due to disability or specific medical conditions.

Coverage for People with Disabilities: Medicare also covers certain individuals under the age of 65 who have been receiving Social Security Disability Insurance (SSDI) benefits or Railroad Retirement Disability benefits for at least 24 months. Individuals with certain disabilities, such as ALS (Lou Gehrig's disease) or ESRD (end-stage renal disease), may qualify for Medicare coverage sooner.

Parts of Medicare:

Medicare Part A (Hospital Insurance): Covers inpatient hospital stays, skilled nursing facility care, hospice care, and some home health services.
Medicare Part B (Medical Insurance): Covers doctor visits, outpatient care, preventive services, durable medical equipment, and some home health services.
Medicare Part C (Medicare Advantage): Allows beneficiaries to receive their Medicare benefits through private health insurance plans, such as Health Maintenance Organizations (HMOs) or Preferred Provider Organizations (PPOs), that contract with Medicare to provide Part A and Part B benefits.
Medicare Part D (Prescription Drug Coverage): Provides coverage for prescription drugs through private insurance plans approved by Medicare. Part D plans can be added to Original Medicare or included in Medicare Advantage plans.

Costs and Premiums: While Medicare Part A is generally available without premiums for most beneficiaries who have paid into Social Security or Medicare taxes, Medicare Part B, Part C, and Part D may require monthly premiums, deductibles, copayments, and coinsurance. The costs and coverage vary depending on factors such as income, eligibility, and the type of plan chosen.

Enrollment: Most people are automatically enrolled in Medicare Part A and Part B when they turn 65 if they are already receiving Social Security benefits. Others may need to enroll during specific enrollment periods, such as the Initial Enrollment Period, Special Enrollment Period, or Annual Enrollment Period, depending on their circumstances.

Medicare Supplement Insurance (Medigap): Medigap plans are private insurance policies that can help cover certain out-of-pocket costs not covered by Original Medicare, such as copayments, coinsurance, and deductibles. Medigap plans are sold by private insurance companies and work alongside Original Medicare.