The capability approach is relevant to gaining a conceptual understanding of individuals’ abilities and motivation to work and to explore the potential consequences that various working conditions have for people when they reach old age. Here, the capability concept is complemented with system theory to understand the multi-component key resources for capability to work among older workers, and also the conversion factors – capability through work – at individual, micro, meso, macro and chrono-levels. The theoretical approach is exemplified by studies from the interdisciplinary field of work sciences. The chapter describes central working-life conditions, conversion factors for crafting capability to work and examples of patterns of interactions between capability to work and capability through work. To support practical applications, we suggest important conversion factors and patterns of interaction between capability to work and capability through working-life resources. In sum, having a reasonable degree of control and influence (freedom of choice) at work and opportunities to make individual deals and adjustments that match one’s values, abilities, competence and experience are important for individual preference of a long working life. This requires an organisation that focuses on the value of work and promotes a general learning climate through broad participation.