Social prejudice, family nonacceptance, and lack of marriage or adoption rights often restrict the formation of conventional social ties among LGBT older adults. As a result, they often rely on families of choice constituted by other LGBT/age peers for support. Using a series of regression analyses with a national sample of LGBT older Americans, this study investigated how characteristics of social network structure (size and composition - LGBT vs. non-LGBT identity and age ≥50 vs. < 50) were related to LGBT older adults’ social network function (perceived social support). Larger social networks, especially those composed of LGBT members and older adults, were associated with more perceived social support. In subgroup analyses, larger social networks composed of more LGBT members and older adults were associated with more perceived social support among lesbian and gay respondents. For bisexual + older adults, larger social network size was associated with more perceived social support, but social network composition was not related to more perceived social support. For transgender older adults, neither social network size nor network composition were significantly associated with perceived social support. This study demonstrated that having more people with similar characteristics in their social networks cues LGBT older adults about the availability of social support. Findings may inform strategies for tailoring programs intended to maintain and strengthen LGBT older adults’ social support networks.