Background: Incorporating behavioral health care into patient centered medical homes is critical for improving patient health and care quality while reducing costs. Despite documented effectiveness of behavioral health integration (BHI) in primary care settings, implementation is limited outside of large health systems. We conducted a survey of BHI in primary care practices participating in the Comprehensive Primary Care (CPC) initiative, a four-year multi-payer initiative of the Centers for Medicare and Medicaid Services (CMS). We sought to explore associations between practice characteristics and the extent of BHI to illuminate possible factors influencing successful implementation. Method: We fielded a survey that addressed six substantive domains (integrated space, training, access, communication and coordination, treatment planning, and available resources) and five behavioral health conditions (depression, anxiety, pain, alcohol use disorder, and cognitive function). Descriptive statistics compared BHI survey respondents to all CPC practices, documented the availability of behavioral health providers, and primary care and behavioral health provider communication. Bivariate relationships compared provider and practice characteristics and domain scores. Results: One hundred sixty-one of 188 eligible primary care practices completed the survey (86% response rate). Scores indicated basic to good baseline implementation of BHI in all domains, with lowest scores on communication and coordination and highest scores for depression. Higher scores were associated with: having any behavioral health provider, multispecialty practice, patient-centered medical home designation, and having any communication between behavioral health and primary care providers. Conclusions: This study provides useful data on opportunities and challenges of scaling BHI integration linked to primary care transformation. Payment reform models such as CPC can assist in BHI promotion and development.