Objectives. To describe and report initial outcomes of a low-threshold, group-based primary care medication for opioid use disorder (OUD) program in a federally qualified health center.Methods. We performed a retrospective chart review of patients enrolled in the program from October 4, 2017, to October 3, 2018, in Philadelphia, Pennsylvania. The main outcome measure was time retained in treatment, defined as time from treatment initiation to unplanned treatment termination. Secondary outcomes were the relationships between treatment retention and cocaine use or housing status. We analyzed retention in treatment using Kaplan-Meier survival estimates.Results. The 3- and 6-month retention rates were 82% and 63%, respectively. The log-rank test showed no significant differences for comparisons between homeless versus not homeless (P = .25) and cocaine use versus no cocaine use (P = .12).Conclusions. The medication for OUD program engaged a large number of patients from marginalized groups. Three- and 6-month retention rates were comparable with those reported of other federally qualified health center populations.Public Health Implications. Integrating treatment of OUD into primary care shows promise for increasing access to and retention in medication for OUD services. The federally qualified health center payment structure supports the sustainability of the group visit model.