What is a joint federal and state program that provides health care coverage to low-income populations?

The correct choice is Medicaid because it is explicitly designed as a joint federal and state program to deliver healthcare services to low-income individuals and families. Established under the Social Security Act, Medicaid's funding and administration are shared between the federal government and each state, allowing for flexibility in the delivery of services based on the specific needs of the population each state serves.

Medicaid covers a wide range of health services, including hospital visits, long-term care, and preventative services, which are crucial for the low-income population it aims to assist. It also has eligibility requirements that are primarily based on income and family size, effectively providing a safety net to those who might otherwise be unable to afford necessary medical care. This partnership structure between federal and state levels is a key feature that distinguishes Medicaid from other programs, reinforcing its role in addressing health disparities among low-income individuals.