Drawing on publications produced by one of the oldest and leading professional associations dealing with intellectual disability (ID), this paper explores the continual maintenance of expertise over potentially contested classifications. I find that, given unforeseen difficulties among professionals in actually defining and classifying what is currently known as ID as well as the later addition of new stakeholders in the advocacy field, professionals' understanding of revision shifted over time from a problem to ultimately be solved to a "legacy of revision" used to explain past changes in criteria and anticipate further ones. In analyzing this legacy, I focus on professionals' understanding of several shifts surrounding diagnostic and classification criteria over the course of the twentieth and into the twenty-first century. To the extent that previous literature suggests that ambiguities surrounding classification are to be expected, this paper shows how professionals in the ID field drew on resonant themes and rhetorically (re)framed past and future changes in their maintenance of expertise in a field that dramatically shifted in what was acceptable in the treatment of people with disabilities.
