This chapter reviews the conceptual and empirical basis for the assessment of legal capacities in older adults. Legal capacities (formerly called competencies) are distinguished from the important conceptual, empirical, and clinical work to date in defining, measuring, and maintaining functional everyday competence. In this chapter, the term clinical "capacity" refers to a professional clinical judgment as to whether a specific individual has the requisite cognitive, decisional, affective, and practical abilities to adequately complete a specific task or make a specific decision. This chapter summarizes a framework for clinical assessment. Nine components necessary for clinical capacity assessment of older adults are-legal Standard, functional elements, diagnosis, cognitive underpinnings, psychiatric or emotional factors, values, risk considerations, steps to enhance capacity, and clinical judgment of capacity. These are explained in the chapter. To optimize the understanding of capacity and its application in clinical practice and law, vigorous collaboration between clinical and legal professionals (e.g., attorneys, judges, courts) should continue to be encouraged. Additionally, enhancing knowledge about capacity in the general population will be useful to assist individuals in planning for future incapacities, recognizing diminished capacity in their loved ones, and to protect vulnerable adults from elder abuse and exploitation. © 2011 Copyright © 2011 Elsevier Inc. All rights reserved.