Although occupational therapists historically acknowledged contributions of the environment to the maintenance of productive behavior, their literature has only recently begun to illustrate the interrelationships between persons and settings. Incorporating environmental themes into the model of occupation broadens an examination of the concept of occupational performance and helps establish the clinic as a therapeutic milieu. This paper considers three facets of person-environment interactions: environmental properties that influence the volition subsystem and the person’s decision to enter a setting; the influence of the setting’s demands for performance on the development of roles, habits, and skills; and factors affecting the individual’s engagement in an expanding range of occupational settings.