This article addresses birth and the recognition of personhood. It is about the calculated acts of recognition that take place at the beginnings of life when the obligation to protect and extend physical care is uncertain. It examines these dilemmas from the perspective of clinicians and scientists who assist in birth through their work with embryos, fetuses, and extremely premature infants in the United States. Through multisited ethnography and in-depth interviews at a leading U.S. teaching hospital, this article argues that the concept of viability operates as a placeholder for the recognition of personhood at the beginnings of life. Articulated in a language of survival and stratified by gestational age, this article explores how viability is a central organizing principle in the management of birth. It aims to situate questions about the value of life to the maternity unit where patients and clinicians face choices about the kinds of viability—and as a result persons—that are possible and desired within the contemporary culture of hospital births.