Implementing state auditor recommendations for reducing improper medicaid concurrent enrollment payments.

SB 5258 requires Washington's Medicaid agency and state auditor to collaborate with managed care organizations to prevent duplicate Medicaid enrollments across states, which causes unnecessary payments. Key provisions mandate that private health plans monthly identify individuals enrolled in multiple state Medicaid programs, recover premiums for those who moved out of state, and report findings annually starting in 2027. The bill also directs agencies to use national address databases to track residents who relocate out of state and requires a state auditor performance audit by 2031 to assess progress. These changes directly affect Washington's Medicaid program and the private health plans contracted with the state, aiming to reduce improper payments through systematic tracking and reporting.