Objective To examine the roles of facility‐ and state‐level factors in treatment facilities' adoption and diffusion of pharmaceutical agents used in addiction treatment. Data Sources Secondary data from the National Survey of Substance Abuse Treatment Services (N‐SSATS), Substance Abuse and Mental Health Services Administration (SAMHSA), Centers for Medicare and Medicaid Services, Alcohol Policy Information System, and Kaiser Family Foundation. Study Design We estimate ordered logit and multinomial logit models to examine the relationship of state and treatment facility characteristics to the adoption and diffusion of three pharmaceutical agents over 4 years when each was at a different stage of adoption or diffusion. Data Collection N‐SSATS data with facility codes, obtained directly from SAMHSA, were linked by state identifiers to the other publicly available, secondary data. Principal Findings The analysis confirms the importance of awareness and exposure to the adoption behavior of others, dissemination of information about the feasibility and effectiveness of innovations, geographical clustering, and licensing and accreditation in legitimizing facilities' adoption and continued use of pharmacotherapies in addiction treatment. Conclusions Policy and administrative levers exist to increase the availability of pharmaceutical technologies and their continued use by substance abuse treatment facilities.