This paper presents a conceptual model of physical independence and dependence as it relates to adult onset, chronic physical illness and disability. Physical independence and dependence are presented as two separate, continuous, and multiply determined constructs, and illustrations are provided of situations where people can be independent, dependent, not independent, or experience imposed dependence. The paper also discusses potential determinants of physical independence and dependence, including different domains of disability, the role of subjective perceptions, demographics, the physical and social/political environments, personal resources, attitudes and coping resources, illness and efficacy appraisals, and the nature of the assistive relationship. The paper extends work on physical independence and dependence by synthesizing the findings from previous studies and incorporating the findings from other relevant areas of research into the area. It also expands on the concepts of physical independence and dependence, as well as their determinants, and relates independence and dependence to other outcomes of interest such as service delivery.