Patricia Smith provides an analysis of the concept of omission that builds upon the work of Joel Feinberg. Her account succeeds in bringing together more systematically than did Feinberg several key elements of his analysis. She also usefully extends the analysis to include unintentional omissions. Nonetheless, I argue that she mistakenly presupposes that there is a unique and logically fundamental concept of omission. Rather, I contend, there are multiple omission concepts, each mapping the conceptual terrain of inaction in a somewhat different way. These different concepts, each useful for a distinct purpose, will emerge from an examination of the flaws that Smith's account shares with Feinberg's analysis.