As managed care achieves greater penetration in the marketplace, increasing attention is being devoted to models of integration and coordination of behavioral health with general medical care. In considering strategies and models, attention must be given to the heterogeneity of patient populations and the fact that successful approaches with some patient populations may not be suitable for others. Six approaches are reviewed: mainstreaming, the liaison psychiatry/collaboration model, new practitioner models, independent carveouts, functionally integrated carveouts, and extended care models. Each offers potentials and limitations, but little outcome data are available. Managed care models are diverse and changing rapidly. Much depends on the commitments of managers and professionals to the collaborative process and the extent to which incentives are consistent with clinical goals. Despite the uncertain and changing environment, it is clear that primary care physicians will remain significant providers of mental health services if for no other reason than many patients will resist referral to specialty mental health providers.