Much research on disability has focused on individuals with congenital anomalies and birth defects, and has emphasized the medical aspects of various impairments. Investigations have centered on the treatment and management of problematic physical symptoms with little attention given to the meaning of disabilities for people's family and social relationships. The literature fails to reflect a recognition that most disabling conditions occur later in life as a result of injury or illness and are inadequately defined or described in singularly negative terms. This study was undertaken to examine how adult-onset disability is experienced in various social contexts, and to consider how individuals who become disabled in adulthood and their family members develop an understanding of what disability means, beyond consideration of medical care and physical treatment. Qualitative data were collected from a purposive sample of 9 intimate couples in which one of the partners had been diagnosed with multiple sclerosis. Indepth conjoint interviews were conducted with each couple, followed by private interviews with the 18 individual partners, rendering different perspectives on disability as a personal and familial experience. The results indicate that disability onset in middle adulthood is an important, but not all-encompassing, experience that shapes the individual lives of those affected and their loved ones, as well as their shared life as a couple. Contrary to much research that frames disability in tenns of stress or deficit models which assume negative and problematic experience, the results of this investigation indicated that disability is perceived as having some positive aspects on personal and family development. The data indicated that disability is a process that takes place over time and through which people's perceptions and experiences are altered, as opposed to a being a permanent identity or status that occurs as a result of a discrete event. / Ph. D.