There has been a gradual shift from a deficit to a support model for understanding disability over the last two decades. Although more attention is focused on supports at the individual level, policy has provided for the provision of family support. Despite this policy, families' needs for support are on the rise; and research suggests that families of children with severe and multiple disabilities may be at the highest risk for unmet need. This review synthesizes literature published between 1990 and 2010 that reported the relationship between family support and family outcomes (family functioning, family satisfaction, family quality of life, and family stress) for families of children with moderate to severe disabilities. We also report the conceptualization and measurement of family support in the research literature included in the review. Findings showed that (a) across studies, family support was significantly related to family outcomes; (b) there was wide variability in the types and sources of support assessed; and (c) operational definitions of family support were lacking. A discussion of the findings, including limitations of the review, themes, and implications are provided. (Contains 3 tables.)