In this article I use Margaret Lock's concept of local biology as a standpoint to view tuberculosis as a threshold where distinctions between social and biological aspects of disease are negotiated. I conceptualize tuberculosis as a threshold in two ways: first as a passageway, and second as a space for navigating the limits of tolerance to therapeutics. The article is based on ethnographic research about responses to tuberculosis in post-Soviet Georgia. I focus on how health professionals and patients make claims to social aspects of illness by recuperating historical examples for tuberculosis treatment as a moral commitment to society, and in the context of emergent patient-centered treatment services.