The World Health Organization has developed the Integrated Care of Older People (ICOPE) strategy, a program based on the measurement of intrinsic capacity (IC) as “the composite of all physical and mental attributes on which an individual can draw”. Multicomponent interventions appear to be the most effective approach to enhance IC and to prevent frailty and disability, since adapted physical activity is the preventive intervention that has shown most evidence in the treatment of frailty and risk of falls. Our paper describes the development of a multi-domain group-based intervention addressed to older people living in the community, aimed at improving and/or maintaining intrinsic capacity by means of promoting physical activity, healthy nutrition, and psychological wellbeing in older people. The process of intervention development is described following the Guidance for reporting intervention development studies in health research (GUIDED. The result of this study is the AMICOPE intervention (Aptitude Multi-domain group-based intervention to improve and/or maintain IC in Older PEople) built upon the ICOPE framework and described following the Template for Intervention Description and Replication (TIDieR) guidelines. This study represents the first stage of the UK Medical Research Council framework for developing and evaluating a complex intervention. The next step should be carrying out a feasibility study for the AMICOPE intervention, and in a later stage, assessing the effectiveness in a randomized controlled trial.