Background: The Residential Medication Management Review (RMMR) service is a large investment by the Australian government and involves considerable time commitment. Objectives: This study determined the impact of RMMRs on the use of potentially inappropriate medications (PIMs), benzodiazepines and antidepressants, described patterns of PIM use, and examined costs. Methods: The study included 5576 participants from the Australian Longitudinal Study on Women's Health from 2005 to 2017. Three generalised estimating equation (GEE) models were specified to separately analyse the impact of RMMRs on the use of PIMs, benzodiazepines and antidepressants. Descriptive statistics were used to present, at each year, the proportions of participants with PIMs, patterns of PIMs and costs of PIMs. Results: There was no evidence for an association between the use of RMMRs and the use of PIMs (OR = 0.99; 95% CI = 0.88, 1.11), benzodiazepines (OR = 1.02; 95% CI = 0.95, 1.08) or antidepressants (OR = 0.99; 95% CI = 0.90, 1.10) in the following year. There were few differences in the use of particular classes of PIMs, nor any differences in the median benefits paid by government or out-of-pocket costs, between participants who did and did not receive RMMRs. There was a slight increase in median OOP costs and a decrease in government benefits over time. Conclusions: There was a lack of long-term changes on use of PIMs, however, its appropriate use must be considered during RMMRs. Healthcare professionals have an obligation to optimise the service to reduce medication costs whilst improving health outcomes among individuals residing in RACF.