Importance: Emergency department (ED)-initiated buprenorphine for the treatment of opioid use disorder (OUD) is underused.

Question: Does implementation facilitation (IF) increase adoption of emergency department (ED)–initiated buprenorphine and patient engagement in opioid use disorder treatment compared with grand rounds?

Findings: In this nonrandomized hybrid type 3 effectiveness implementation trial conducted in 4 urban, academic EDs comparing 394 patients enrolled during a baseline evaluation period after grand rounds and 362 patients enrolled during an IF evaluation period, rates of ED-initiated buprenorphine and engagement in OUD treatment at 30 days were higher during the IF period.

Meaning: These findings suggest that IF was associated with greater rates of ED-initiated buprenorphine and patient engagement in treatment at 30 days compared with grand rounds.