SB 657 proposes to expand Medicaid eligibility in Texas to include all individuals for whom federal matching funds are available under federal law. The bill mandates the executive commissioner of the Health and Human Services Commission to prepare and seek a waiver to the state Medicaid plan, focusing on maximizing health care access, reducing the uninsured population, enhancing service delivery efficiency, increasing accessibility to health care services, promoting personal responsibility, and lowering health care costs. The bill's implementation is contingent upon obtaining the necessary federal waivers.