Victoria Kemanian, Rosina Watson, Andrew Angus
Despite widespread sustainability commitments, many firms struggle to translate intention into action. This persistent intention–action gap suggests limitations in prevailing accounts of how sustainability is integrated into strategic management that tend to emphasize top-down structures, formal systems and senior leadership. We draw on insider change agency and micro-foundations research to examine how individuals across organizational levels contribute to sustainability integration. Based on a comparative study of three multinational firms, we develop a maturity-contingent model of sustainability integration. We identify a set of top-down and bottom-up micro-strategies that individuals enact, and four mechanisms through which these micro-strategies achieve integration: finding common ground, spatial-temporal ringfencing, establishing sense of ownership and enabling self-efficacy. We show that sustainability integration emerges from shifting configurations of micro-strategies shaped by maturity-dependent opportunity structures. By theorizing how individual actions combine to embed sustainability into organizations, we advance research on corporate sustainability, its micro-foundations, and insider change agency.