This study aimed to inform a measurement approach for older persons who wish to engage in active living such as participating in a walking program. The Patient Generated Index, an individualized measurement approach, and directed and summative content analyses were carried out. A sample size of 204 participants (mean age 75 years; 62% women) was recruited; it generated 934 text threads mapped to 460 unique categories within 45 domains with similarities and differences for women and men. The Capability, Opportunity, Motivation, and Behaviors Model best linked the domains. The results suggest that older persons identify the need to overcome impaired capacity, low motivation, and barriers to engagement to live actively. These are all areas that active living programs could address. How to measure the outcomes of these programs remains elusive.