This article demonstrates how cultural ideologies of language, and the semiotic processes that mobilize them, manifest in contemporary American drug treatment. Drawing from an ethnographic study of an outpatient program in the Midwestern United States, it focuses on therapists' claims about what constitutes “healthy language.” It is argued that these claims both stem from and actively reproduce an “ideology of inner reference,” which presumes that “healthy” language refers to preexisting phenomena, and that the phenomena to which it refers are internal to speakers. By formally discouraging talk that could point outside the parameters of the individual psyche, the treatment program effectively insulates itself from clients' critiques and challenges. A broad attempt is made to elucidate the connection between a language ideology that enjoys wide cultural circulation as well as significant currency in contemporary clinical practice, and a particular political effect called “institutional insulation.”My thanks to Barbara Johnstone and two anonymous reviewers for their insightful, critical comments on an earlier version of this article. I am especially grateful to James Wilce for his keen advice on how to refine central elements of the argument and his guidance toward relevant, fruitful literature. The following people contributed significantly to the essay's development (though its remaining flaws are very much my own): Giorgio Bertellini, Webb Keane, Daniel Listoe, Beth Reed, Douglas Rogers, Michael Sosin, and Sarah Womack. I'd also like to thank the University of Chicago Anthropology Department, Center for Gender Studies, Committee on Human Development, and School of Social Service Administration for opportunities to present (and rethink) earlier versions. The research reported here was conducted with the support of a training fellowship from the National Institute of Mental Health and various grants from the Department of Anthropology, the Institute for Research on Women and Gender, the Program in Women's Studies, Rackham Graduate School, and the School of Social Work, all at the University of Michigan. This essay is for “Lila.”