SB 1578 creates a health care provider participation program in counties with a population of more than 900,000 that border two counties with populations over two million. The program allows counties to collect mandatory payments from nonpublic hospitals to fund a local provider participation fund, which may be used for Medicaid supplemental payment programs and uncompensated care reimbursements. The bill requires public hearings before assessing mandatory payments, ensures funds are not used to expand Medicaid eligibility, and limits the administrative costs counties may charge.