OBJECTIVES: To assess the effect of a cost-management component in a Medicare Part D MTM administrator-implemented program on total prescription drug costs over 3 years. METHODS: The Targeted Intervention Program (TIP) monitors prescription claims data to identify opportunities for cost saving and care improvement, and then periodically generates an electronic TIP-record that notifies the patient’s pharmacy of the situation.  Pharmacists may successfully complete the TIP-record action (e.g. delivering a targeted medication review), return the TIP-record without completion (e.g. lack of patient or provider cooperation), or ignore it.  A cohort of Medicare Part D beneficiaries (N = 16,180) from two drug plans participated in the cost-management component of this program.  Their TIP records from 2010 to 2012 were analyzed using SAS.  Total prescription drug cost, averaged over 3-month period in order to smooth the sporadic nature of prescription fills, was modeled as a function of the cumulative number of generated, returned, and successful TIP-records, time period, beneficiary age, gender, and drug plan (MA-PD, PDP).  A generalized linear mixed model was fitted for the assessment, using AIC for model selection.  RESULTS: Each additional TIP-record generated was significantly associated with a higher total drug cost (p < .0001); however, this effect was attenuated over time, as would be expected when the TIP-record was successfully acted upon.  A successful TIP-record was associated with an 18% reduction in cost at the beginning of the study, falling to 7% at 18 months.  On average, MA-PD beneficiaries had a cost which was 1.62 times higher than those from the PDP; male beneficiaries had an average cost which was 4.8% higher than their counterparts. CONCLUSIONS: Cost-management TIP-records demonstrated a significant decrease in total prescription drug cost upon successful completion, suggesting targeted medication reviews could be used as a drug cost saving strategy for Medicare Part D plans.