This paper examines the role of physicians' progress notes in the professional socialization of medical residents. As a component of their specialty training, residents are principally responsible for making the physician entries in the medical charts of the patients who are under the joint care of the residents and the hospital's medical staff. This includes the initial physician chart entry, the comprehensive 'admit note' which records the initial assessment of the patient upon presentation for medical care. Admit notes, which complement the oral case presentations that they reproduce, constitute a key training tool by means of which residents experience and internalize the cognitive processes which constitute medical reasoning and analysis. However, although a number of researchers have examined residents' oral case presentations, their written communications have seldom been studied. This paper examines the generic conventions that structure residents' admit notes, including abbreviations, telegraphic syntax, the 'SOAP' format, and reliance on background knowledge. Through the analysis of an admit note written by a first-year obstetrical resident, this paper demonstrates how the ability to operate these conventions evidences both the resident's professional socialization and the growth of his or her clinical judgment.