OBJECTIVES: This metareview identifies the common elements associated with published behavioral health-physical health (BH-PH) collaboration/integration strategies for managing comorbid conditions. METHODS: PubMed, Cochrane Library, and the Academy (AHRQ) were searched using keywords “review” or “meta-analysis” and any combination of: “collaboration,” “integrated,” “behavioral,” “mental,” “primary care,” "general practice,” “depression,” “schizophrenia,” “bipolar,” “panic,” anxiety,” “alcohol,” and “substance abuse.” RESULTS: The search identified 110 systematic reviews and/or meta-analyses covering BH-PH collaboration/integration strategies, referencing almost 3,000 studies. Most studies addressed integration of BH services into primary care (PC), primarily major depression (less frequently anxiety, somatization, alcohol and addiction disorders) in adults and/or elderly. Some described integration of BH services into outpatient and community settings—effective venues for strategies like diet and exercise—or PH services in BH settings. Provider integration strategies usually included a psychiatrist or clinical psychologist available for PC consultation, but also therapists, BH-trained clinical nurses, social workers, care managers, and/or community health workers. Integrated BH-PH care models achieved clinically meaningful improvements in depression- and anxiety-related primary and secondary outcomes. Recent individual studies have also reported improvements in medical/clinical outcomes (e.g., HbA1c in TEAMcare study) and physical functioning. The extent of integration was not significantly associated with depression or anxiety outcomes. No best practices (e.g., colocation) have been definitively validated as significant predictors for promoting positive health outcomes; rather, successful strategies implement multifaceted, system-level interventions, including brief psychological therapies (e.g., motivational interviewing). The effectiveness of BH screening in PC settings is related to the availability of adequate treatment and follow-up systems of care. CONCLUSIONS: Increasing evidence is available concerning the effectiveness of BH-PH integration/collaboration strategies in treating depressive and anxiety symptoms and medical/clinical outcomes. Improved stratification of BH-PH integration models will determine the relative success of different integration approaches. Additional studies are needed in adolescents and people with schizophrenia and bipolar disorder.