Background A key purpose of the National Aged Care Medication Roundtable is to support quality improvement in residential aged care (RAC) using routinely collected electronic data to generate quarterly medication quality indicator reports for review and benchmarking. Methods A co-design approach was used to develop quarterly reports, which initially included two mandatory national quality indicators: polypharmacy and antipsychotic use. Through feedback cycles among stakeholders, indicator definitions, data visualisation, benchmarking approaches and interpretive guidance were progressively refined. Semi-automated analytic workflows were developed in SAS to link medication administration and resident profile datasets, calculate indicator rates, and generate benchmarking outputs. Indicators were risk-adjusted to more accurately reflect variation in medicine use across homes with different resident characteristics. Results The indicator set has expanded to include eight medication quality indicators to align with stakeholder-identified priorities. To meet information needs of multiple stakeholders, reports include: (1) rates of medication use for Roundtable aged care providers, with comparisons to national averages where available; (2) provider-level reports comparing providers with each other and with Roundtable means; and (3) home-level longitudinal trend reports showing within-home change over. Three aged care providers, managing 46 homes (48-172 beds), receive quarterly reports that provide the basis for Roundtable meetings, where data are benchmarked, interpreted and discussed in relation to best practice guidelines, care contexts and appropriate actions. Conclusion A structured co-design approach, combined with semi-automated analytics and risk adjustment, has enabled scalable quarterly benchmarking reports that reflect provider priorities, support shared learning and targeted quality improvement in RAC.