Importance: The overdose epidemic continues in the US, with 107 941 overdose deaths in 2022 and countless lives affected by the addiction crisis. Although widespread efforts to train and support physicians to implement medications and other evidence-based substance use disorder interventions have been ongoing, adoption of these evidence-based practices (EBPs) by physicians remains low.

Question: What reasons do physicians give for not addressing substance use and addiction in their clinical practice?

Findings: In this systematic review of 283 articles, the institutional environment (81.2% of articles) was the most common reason given for physicians not intervening in addiction, followed by lack of skill (73.9%), cognitive capacity (73.5%), and knowledge (71.9%).

Meaning: These findings suggest effort should be directed at creating institutional environments that facilitate delivery of evidence-based addiction care while improving access to both education and training opportunities for physicians to practice necessary skills.