Medicare insurance is a federal health insurance program in the United States primarily for people aged 65 and over, as well as for some younger individuals with disabilities or specific medical conditions. It consists of different parts: Part A covers hospital and inpatient services; Part B covers outpatient services, including doctor visits and preventive care; Part C, or Medicare Advantage, offers alternative ways to receive Medicare benefits through private insurance companies; and Part D covers prescription drug costs. The program helps with the cost of health care, but it does not cover all medical expenses or the cost of most long-term care.