Since the 1990s, notions of corporate social responsibility (CSR) have been shaped by the global diffusion of citizenship practices and the advent of a corporate sustainability community that encourages firms to improve their environmental and social performance.These understandings of CSR have recast corporate responsibility away from a liability model to one that places a moral obligation on firms to address the societal ills connected to global markets.We analyse the CSR reports of large German and US firms published from the mid-1990s to 2013 to gauge how multinational firms’ understandings of their obligations have evolved in light of this changing normative environment.We find that many firms have expanded how they define their responsibilities, but these global CSR norms have been grafted onto nationally determined notions of to whom corporations are responsible and on what basis. Despite these national differences, firms in both countries have engaged more substantively with environmental than social sustainability and are more likely to describe their responsibilities for the environment in terms of an ethics of care.