Substance abuse treatment clients present with an array of service needs in various life domains. Ideal models of addiction treatment incorporate provision or linkages to services to meet clients' multiple needs; in turn, these wraparound and supportive services are associated with improvements in client retention and treatment outcomes. Using data from large samples of specialty addiction treatment providers in the public and private sectors, this article examines the extent and organizational correlates of the comprehensiveness of service delivery. Multivariate models indicate that private sector treatment facilities offer more "core" medical and treatment services, whereas public sector programs offer more wraparound and supportive services. However, both sectors fall short of the ideal model of service comprehensiveness in terms of absolute number of services offered. These findings raise concerns regarding the quality and availability of needed services for treatment of addiction.