There is growing global evidence on the utility of the WHO Intrinsic Capacity Framework to monitor and promote healthy ageing. Healthy ageing means maintaining functional ability to do things that one values, determined by a person’s intrinsic capacity and their environment. Intrinsic capacity includes psychological capacity; however this construct has never been defined in the context of healthy ageing, and there are no validated measures for clinical assessment or population monitoring. This study aimed to establish a core list of attributes of psychological capacity, to inform development of a measurement tool. A modified Delphi approach comprising two rounds of online surveys was conducted. A combined purposive and snowball sampling strategy was used to recruit people with clinical, academic, government or advocacy expertise in healthy ageing from six WHO regions. Participants were asked to consider a list of potential attributes and indicate whether each should be included or modified. The threshold for consensus was set a priori at 75%. Participants were also invited to provide qualitative input and suggest additional attributes. This presentation will share findings from the Delphi study, including a list of attributes of psychological capacity for healthy ageing. This study is a critical element in the development of a tool to measure psychological capacity and will be used in concert with findings from a qualitative exploration with the target population, to develop a measure for subsequent validation and translation. The tool will enable evaluation of psychological capacity interventions, and monitoring of global efforts to advance healthy ageing.