For people living with long-term physical disability (LTPD) social participation may involve managing physical impairments and secondary health conditions (SHCs) that are not due to the pathophysiology of the LTPD diagnosis itself. Prior research found a negative relationship between SHCs and participation in social roles in people with spinal cord injury (SCI). We expand on this research by investigating the influence of SHCs on participation in social roles for people with one of four LTPDs, controlling for co-variates. We (1) evaluated the associations between SHCs and participation in social roles; and (2) determined whether SHCs on individuals' ability to participate in social roles varies by type of diagnosis in those aging with either SCI, muscular sclerosis, muscular dystrophy, or post-polio syndrome. Cross-sectional, secondary data analysis from a return-by-mail survey. N = 1,573. Data were analyzed with multiple linear regressions (hypothesis 1), and then three moderated regressions (hypothesis 2). After controlling for demographics, SHCs were associated with lower ability to participate in social roles and accounted for 48% of the variance (all p's <.001). The relationship between depression and social role participation was moderated by diagnosis, such that depression was more negatively associated with social participation among individuals with SCI (p = .020). Thus, SHC negatively impact participation in social roles.