In terms of number of beneficiaries, Medicaid is the single largest health insurance program in the US. Along with the Children’s Health Insurance Program (CHIP), Medicaid covers nearly half of all births and provides health insurance to nearly half of the children in the country. This article provides a broad introduction to Medicaid and CHIP for the pediatric radiologist with a special focus on topics relevant to pediatric imaging and population health. This includes an overview of Medicaid’s structure and eligibility criteria and how it differs from Medicare. The paper examines the means-tested programs within the context of pediatric radiology, reviewing pertinent topics such as the rise of Medicaid managed care plans, Medicaid expansion, the effects of Medicaid on child health, and COVID-19. Beyond the basics of benefits coverage, pediatric radiologists should understand how Medicaid and CHIP financing and reimbursement affect the ability of pediatric practices, radiology groups, and hospitals to provide services for children in a sustainable manner. The paper concludes with an analysis of future opportunities for Medicaid and CHIP.