Conflict over work boundaries between occupations occurs when one occupation encroaches on the work functions of another occupation (the “dominating occupation”). Encroachment efforts originate from the strategic responses of occupations to environmental changes. The dominating occupation (or internal segments of it) opposes encroachment efforts to the extent that economic survival of the dominating occupation is threatened. Encroachment efforts heighten in intensity as the number of members of the encroaching occupation who receive education in the dominating occupation's knowledge base grows. In the case of state-regulated occupations, the political system plays a major role in the resolution of the disputes, and the political outcomes of the interoccupational conflicts depend upon both the interest group resources of the competing occupations and legislators' judgments about the competence of the encroaching occupation to perform the disputed task. This framework is illustrated using the case of optometry's attempt to expand its work boundaries to include the application of drugs to the eye. © 1987, SAGE PUBLICATIONS. All rights reserved.