Objective: To characterize changes in medication therapy management (MTM) interventions across time, including identification of trends associated with the provision of pharmacist-provided MTM services and evaluation of potential cost savings from avoidance in health care utilization resulting from pharmacist-provided MTM services. Methods: Pharmacist generated claims from a multi-state MTM company were analyzed across a seven-year time period. Data extracted from each claim included patient demographic information (e.g., age and gender), specific information about the medication triggering the intervention (e.g., therapeutic class and therapy type), and specific information about the service provided (e.g., reason for service, professional service provided, result of service, and estimated cost avoidance (ECA) associated with the MTM intervention). In addition, pharmacy payment information was extracted, so that along with ECA, an estimated return on investment for each claim could be calculated. Results: A selected subsample containing over 75,000 MTM claims submitted by pharmacists in 47 states from years 2000 through 2006 were analyzed. The reason for pharmacist-provided MTM intervention moved away from new/changed drug therapy to cost efficacy management, while actions shifted from patient education/follow up to provider consultations (P<0.01). Services also shifted towards claims involving chronic type medications and away from acute type medications (P<0.01), resulting in significant changes in the therapeutic classes and older patients being served (P<0.01). These trends resulted in higher pharmacy reimbursements, greater cost avoidance, and larger average returns on investment per claim across time (P<0.01). Conclusion: MTM interventions over a seven year period evolved from the provision of traditional patient education involving acute medications towards consultation-type services for chronic medications. These shifts suggest the provision of MTM services will be increasingly vital as the population ages. Further, these trends suggest that pharmacists will be provided with increasing opportunities to provide MTM services and receive higher reimbursements for performing these services.