ImportanceThe coronavirus disease 2019 (COVID-19) pandemic prompted policy changes to allow increased telehealth delivery of buprenorphine, a potentially lifesaving medication for opioid use disorder (OUD). It is unclear how characteristics of patients who access different treatment modalities (in-person vs telehealth, video vs telephone) vary, and whether modality is associated with retention—a key indicator of care quality.ObjectivesTo compare patient characteristics across receipt of different treatment modalities and to assess whether modality was associated with retention during the year following COVID-19–related policy changes.Design, Setting, and ParticipantsThis cross-sectional study was conducted in the national Veterans Health Administration. Participants included patients who received buprenorphine for OUD during March 23, 2020, to March 22, 2021. Analyses examining retention were stratified by buprenorphine initiation time (year following COVID-19–related changes; prior to COVID-19–related changes).ExposuresPatient characteristics; treatment modality (at least 1 video visit, at least 1 telephone visit but no video, only in-person).Main Outcomes and MeasuresTreatment modality; 90-day retention.ResultsAmong 17 182 patients, 7094 (41.3%) were aged 30 to 44 years and 6251 (36.4%) were aged 45 to 64 years; 15 835 (92.2%) were male, 14 085 (82.0%) were White, and 16 292 (94.8%) were non-Hispanic; 6547 (38.1%) had at least 1 video visit, 8524 (49.6%) had at least 1 telephone visit but no video visit, and 2111 (12.3%) had only in-person visits. Patients who were younger, male, Black, unknown race, Hispanic, non–service connected, or had specific mental health/substance use comorbidities were less likely to receive any telehealth. Among patients who received telehealth, those who were older, male, Black, non–service connected, or experiencing homelessness and/or housing instability were less likely to have video visits. Retention was significantly higher for patients with telehealth compared with only in-person visits regardless of initiation time (for initiated in year following COVID-19–related changes: adjusted odds ratio [aOR], 1.31; 95% CI, 1.12-1.53; for initiated prior to COVID-19–related changes: aOR, 1.23; 95% CI, 1.08-1.39). Among patients with telehealth, higher retention was observed in those with video visits compared with only telephone for patients who initiated in the year following COVID-19 (aOR, 1.47; 95% CI, 1.26-1.71).Conclusions and RelevanceIn this cross-sectional study, many patients accessed buprenorphine via telephone and some were less likely to have any video visits. These findings suggest that discontinuing or reducing telephone access may disrupt treatment for many patients, particularly groups with access disparities such as Black patients and those experiencing homelessness. Telehealth was associated with increased retention for both new and continuing patients.