The government program that provides income to people who are retired is called:

Social Security is a government program designed to provide financial support to individuals who have reached retirement age, ensuring they have a source of income after leaving the workforce. It operates on a social insurance model, where workers contribute a portion of their income throughout their careers, and in return, they receive benefits when they retire. This program helps to maintain a basic standard of living for retirees, offering them financial stability in their later years.

In contrast, Medicare is a health insurance program primarily for individuals aged 65 and older, which covers medical expenses but does not provide income. Selective service refers to the system for registering individuals for potential military conscription and does not offer any income support. Workers' compensation is an insurance program that provides wage replacement and medical benefits to employees injured on the job, which is also unrelated to retirement income.