Data from a national study of 345 privately funded, community-based substance use disorder (SUD) treatment centers were used to investigate social workers' knowledge, perceptions of effectiveness, and perceptions of the acceptability of medication assisted treatments (MATs) for SUDs. Results reveal the importance of exposure to MATs for social workers to develop a knowledge base regarding the effectiveness of various pharmacological agents. Results also underline the importance of social workers' perceptions of effectiveness in forming opinions regarding the acceptability of the use of MATs in SUD treatment. Lastly, a 12-Step orientation toward treatment has a negative influence on social workers' opinions regarding the acceptability of MATs.