Payment by the act imposes an economic rationality on hospital doctors that they spontaneously perceive as invasive and all-powerful. The economy is first apprehended as a foreign body, distorting work and the representations that actors make of it. However, it can take other meanings and other aspects when it is understood as a constitutive element of work, just as is the respect for norms, of the framework setting ethical guidelines, or the technical know-how acquired throughout doctors’ training. By thus understanding the economy, through payment by the act, as a variable entering into the composition of work, it is then possible to grasp the place it occupies in the accomplishment of activities, how the actors manage to neutralize it, and on what condition it acquires legitimacy.