Objective: The need for residential care services will grow significantly over the coming years as the general population in Australia continues to age. The aim of this study was to assess the adequacy of residential care services across New South Wales (NSW), Australia, in relation to the current and predicted future aging population. Method: This study was a secondary data analysis. Existing datasets were compiled for analysis by creation of a temporal geodatabase, with predicted population data from 2019 to 2029 linked to corresponding geographic zones. Results: Demand for operational places was over capacity in 2019, at 101.5%. From 2019 to 2029, this will grow to 120.2% of 2019 capacity by 2024 and to 135.6% by 2029. An additional 25 800 operational places will be required by 2029 to meet targets. During the previous decade of 2008–18, operational places grew by only 11 502 places. Conclusions: NSW was not providing an adequate level of residential aged care and, under current allocations, this problem will worsen substantially over time, with flow-on impacts for the health sector. With aged care reform a current federal government focus, the results of this study may guide decisions that better support the provision of residential aged care. What is known about this topic?: The recently completed Australian Royal Commission into aged care noted widespread system failure and highlighted the gaps in medical services that older Australians were experiencing. What does this paper add?: This paper reports that demand for residential aged care places in NSW was already over capacity in 2019 and that the availability of places varies considerably across the state. Further, an additional 25 800 operational places are required by 2029 to meet government targets. If the growth rate from the past decade is maintained, this will result in a shortfall of 14 298 aged care places in NSW alone. What are the implications?: Without significant increases in the current rate of growth for aged care places, the mainstream medical and health sectors will face significant additional pressures arising from unmet need in both older patients and their informal carers. [ABSTRACT FROM AUTHOR]