Which healthcare insurance is sponsored by the federal government for individuals over 65?

Medicare is a federal health insurance program that primarily serves individuals aged 65 and older. It was established to provide medical coverage to elderly individuals who may have limited or no access to other forms of health insurance. The program consists of different parts that cover aspects such as hospital care, outpatient care, and prescription drugs.

In contrast, Medicaid is a state and federal program aimed at providing health coverage for eligible low-income individuals, which can include certain younger populations, but is not specifically for those over 65. Private insurance refers to plans offered by private companies, which can be purchased by individuals but is not federally sponsored. TRICARE is a healthcare program specifically for active duty military personnel, retirees, and their dependents, which also does not apply to the general population over 65. Thus, the designation of Medicare as the federal program specifically targeting individuals over 65 is what makes it the correct answer.