Class of 2017 Abstract / Objectives: Our working hypothesis is that patients who opt in to pharmacist counseling will have a higher medication possession ratio and longer length on therapy than patients who opt out of pharmacist counseling. Methods: Using data extracted from patient’s charts we retrospectively calculated medication possession ratio and length on therapy in relation to the patient receiving or not receiving counseling. Results: The patients analyzed were receiving 8 specific oral oncolytic medications provided by Avella Specialty Pharmacy in 2015. There were no significant differences found in MPR values for any of the 8 oral oncolytic medications included in the study. Iressa (p=0.826), Lonsurf (p=0.392), Stivarga (p=0.838), Zydelig (p=0.633), Zykadia (p=0.077), Tagrisso (p=0.060), Imbruvica (p=0.263) and Tarceva (p=0.326). No statistically significant differences were found in LOT values for any of the 8 oral oncolytic medications included in the study. Iressa (p=0.885), Lonsurf (p=0.868), Stivarga (p=0.326), Zydelig (p=0.502), Zykadia (p=0.212), Tagrisso (p=0.089), Imbruvica (p=0.540), Tarceva (p=0.129). Conclusions: Pharmacist counseling does not appear to affect MPR or LOT for patients taking oral oncolytic medications. Further research is warranted targeting other chronic disease states with complex oral regimens where medication adherence has not already been established from prior therapy options and adequate disease state knowledge.