In 2010, Veterans Health Administration (VHA) primary care clinics adopted a patient-centered medical home (PCMH) model. This study sought to examine the association between the organizational features related to adoption of PCMH and the level of adherence to oral hypoglycemic agents (OHAs) among patients with diabetes. This retrospective cohort study involved 757 VA clinics that provide primary care to 440,971 patients with diabetes who were taking OHAs in fiscal year 2012. One-year refill-based medication possession ratios (MPRs) were calculated at the patient level. Clinic-level adherence was defined as the proportion of clinics with MPR ≥80%. Risk adjustment of adherence was performed using logistic regression to account for differences in patient populations at clinics. Eight domains of the PCMH model (ie, access, continuity, coordination, teamwork, comprehensive care, self-management, communication, shared decision making) were assessed using items from a previously validated index. Multivariate linear regression was applied to identify PCMH components associated with clinic-level adherence. Patients with diabetes per clinic ranged from 100 to 5011. The average level of adherence to OHAs among clinics ranged from 52.8% to 61.9% (interquartile range = 57.9% to 59.4%). In multivariate analysis, organizational features associated with higher clinic-level adherence included access to routine care (standardized beta [Sβ] = .21, P = .004), having a respectful office staff (Sβ = 0.21, P = .002), and utilization of telephone encounters (Sβ = 0.23, P < .001). Among a national cohort of veterans with diabetes, overall PCMH implementation did not significantly increase adherence to oral hypoglycemic agents, although aspects of implementation were associated with increased adherence. Measures of access to care appear the most significant.