Medicaid Integrated Purchasing for Physical and Behavioral Health: Early Adopters' Perceptions of Payment Reform Implementation in Washington State.

The Centers for Medicare and Medicaid Innovation (CMMI) gave rise to the State Innovation Models (SIMs). Medicaid Integrated Purchasing for Physical and Behavioral Health, referred to as Payment Model 1 (PM1), was a core payment redesign area of the Washington State SIM project under which our research team was contracted to provide an evaluation. In doing so, we leveraged an open systems conceptual model to assess qualitatively Early Adopter stakeholders' perceived effects of implementation. Between 2017 and 2019, we conducted three rounds of interviews, examining themes of care coordination, common facilitators and barriers to integration, and potential concerns for sustaining the initiative into the future. Further, we noted the initiative's complexity may require the establishment of enduring partnerships, secure funding sources, and committed regional leadership to ensure longer-term success.