Efforts to manage healthcare costs include transitioning patients to generic medications. This often includes the statins. Implementation methods and patient selection may affect clinical outcomes of these programs. We measured changes in quality metrics associated with statin transition in high-risk cardiovascular (CV) patients, assessed dose conversion, and identified clinical predictors of successful transition. This retrospective cohort study included adults receiving care in a university health system for ACS, CKD, DM or post- CABG and receiving a statin. Electronic records from 2005 to 2008 were used to identify statin transition (T) or no transition (NT). High (H) and low (L) potency agents, equipotent dosages, and successful transition were defined. Treatment patterns, LDL-C (mg/dL), and medication possession ratios (MPR) were tracked one year after transition. Descriptive, bivariate, and multivariate analyses were applied. The 1,505 patients were 54% male and age 50 + 10 years. Statin transition occurred in 316 (21%) of which 249 (79%) were H to L potency. DM, CKD, ACS, and CABG were present in 70%, 24%, 17%, and 8% of patients. Baseline ACS was present in T (23%) more than NT (15%), p=0.001. Changes in LDL-C were similar in T (+2.2 + 35.4 mg/dL) and NT (-0.4 + 34.6 mg/dL), p=0.34. Adherence (MPR) was higher in T (0.85 + 0.19) relative to NT (0.77 + 0.27), p<0.001. Among T patients, LDL-C goal attainment (<100 mg/dL) and aggressive LDL-C goal attainment (<70 mg/dL) decreased from 65% to 61% (p=0.036) and from 27% to 23% (p=0.015), respectively, from transition to follow-up. For H to L, H to H, L to H, and L to L transitions, LDL-C changes were +8.0 ± 32.2, -36.7 ± 50.5, -24.2 ± 26.9, and -0.2 ± 37.8 mg/dL, respectively (p<0.001). Among H to L transitions, equipotent dose adjustments were made in 174 cases (70%), no adjustment in 44 subjects (18%), and no equipotent dose existed for 31 cases (12%). Adjusted odds of successful transition were higher for equipotent dose transitions (OR 2.83, 95% CI 1.09 to 7.36). In summary, LDL-C control during statin transition in high-risk CV patients is variable, but medication adherence was not diminished. Equipotent dose adjustment is a strong predictor of successful transition but was not made or possible in 30% of patients.