<p>Integrating behavioral health and primary care is a best practice for providing timely access to comprehensive, person-centered services, yet systemic change faces numerous implementation challenges. To overcome these barriers, healthcare systems frequently hire technical assistance (TA) professionals to facilitate implementation. Given the numerous implementation challenges, it is unclear when and how TA providers can most effectively integrate care.&#xa0;The Interactive Systems Framework for Dissemination and Implementation (ISF) and the R = MC² framework were used. Ten participants across the US with experience integrating care represented the three ISF levels: (1) clinicians and healthcare administrators, i.e., ISF delivery system, (2) TA professionals, i.e., ISF support system, and (3) researchers in integrated care and implementation science, i.e., ISF synthesis and translation system. Participants partook in a four-round iterative consensus-building Delphi study to discern which R = MC² determinants could be most improved by TA.&#xa0;Consensus showed that TA may be less relevant for four readiness determinants and highly relevant for improving Observability, or the ability to see that integrating care is improving outcomes. Qualitative results suggest consensus results are valid but may reflect “usual” TA practice rather than the potential effect of systematic, proactive implementation facilitation.&#xa0;The experiences of health system staff, TA providers, and researchers provide indicators for validation and future study on the effect of TA on integrating behavioral health and primary care. Their consensus about which readiness determinants may – and may not – be affected by TA develops hypotheses that can be tested in research and refined in practice.</p>