OBJECTIVES: Much research exists on medication adherence, however, clear evidence is lacking on specific methods to achieve lower rates of non-compliance. The purpose of this study was to evaluate the differences in cholesterol medication adherence at primary care practices who have implemented a patient centered medical home (PCMH) as compared to usual primary care (UPC). METHODS: A retrospective cohort study analyzed medical and pharmacy claims from continuously enrolled Medicare Part D members at least 18 years old at UPMC Health Plan. We compared PCMH and USP practices over a one year period (2011) for medication adherence of statin drugs.  Standardized metrics from the Medicare Health and Drug Plan Quality and Performance Ratings 2012 were used. Exclusion criteria were as follows: switched between PCMH/ UPC practice in 2011; pharmacist on-site at practice; PCMH implemented for < 6 months at practice. Members who had at least 2 fills in the same drug class during the period were included. RESULTS: A total of 1,227 members in 21 PCMH practices were compared to 17,599 members in 1,283 UPC practices. Chi-square tests showed no difference in age, sex or disease burden (using Charleson Comorbidity Index) between the groups.  There was a significant increase in the percentage of members with a medication possession ratio (MPR) of at least 80% for cholesterol medications (75.7% in PCMH vs.72.9% in UPC), p=0.03.   CONCLUSIONS: This research informs investment in the PCMH model which may have an unreported value stream related to medication adherence. The increase in percentage of members with MPR >= 80% in the PCMH group translates to increased CMS star rating of 5. The 5 Star threshold is 75.4%. This is of benefit to the insurer towards the contribution of the overall CMS Star Rating of the Medicare plan, as this metric is weighted three times more than most measures.