The purpose of this article is to determine the effect of medication reviews on patient understanding of and compliance to medications for participants in the Cenla Medication Access Program (CMAP). A sample of 844 individuals with a total of 2013 reviews over a period of 6 months to 1 year produced 5 outcome variables: the percentage of the total number of drugs the patient understands the purpose of (PURPOSE), understands the proper use of (USE), and is compliant with (COMPLIANCE) and the percentage of patients that experienced any drug-drug or drug-disease interactions (INTERACTION) or any adverse reactions (REACTION). Mixed-effects models and generalized estimating equations were used to assess change in PURPOSE, USE, COMPLIANCE, INTERACTION, and REACTION over time. All effects were adjusted for differences in age, race, gender, the number of years of education, total number of medications per patient, and the patient's primary diagnosis. Significant increases were observed for PURPOSE, USE, and COMPLIANCE. A significant decrease was observed for INTERACTION. No significant difference in REACTION was observed over time. CMAP has seen increases in patient understanding and compliance, as well as a decrease in drugdrug and drug-disease interactions through the first year of medication reviews.I NDIVIDUALS AGED 65 YEARS AND OLDER account for a little more than 12% of the US population, yet they consume nearly 25% to 35% of prescription medications. 1,2 Major problems facing the elderly population and all individuals on prescription medications are noncompliance with their medication regimens and adverse drug reactions. 3-5 As a group, the elderly population experiences more adverse drug reactions than any other age group. 1 On average, elderly persons in the United States are on 5 medications, and their risk for a drug-drug interaction can be as high as 50%. 2,6 As many as a quarter of all hospital admissions in elderly persons are drug related. 5 A way of increasing patient compliance and preventing adverse drug events and drug-drug interactions is through medication counseling from a licensed pharmacist. Research has shown that medication reviews and consultations can improve a variety of patient outcomes, including reducing adverse drug events. 7,8 Compliance with drug regimens is particularly important for elderly persons. A randomized trial of community pharmacists educating elderly patients taking 4