Medicaid Expansion refers to a provision of the Affordable Care Act that allows states to extend Medicaid coverage to more low-income individuals and families. This expansion aims to provide health insurance to those who earn too much to qualify for traditional Medicaid but not enough to afford private insurance. States that choose to expand Medicaid receive federal funding to help cover the costs, making it financially beneficial for them. As a result, millions of additional people can access essential health services, improving overall public health and reducing the number of uninsured individuals in the country.