Objective: The objective of the study was to test the hypothesis that the influence of environmental barriers on participation will be fully mediated by psychosocial factors (resilience, grief or loss, and self-efficacy) among individuals with spinal cord injuries and disorders. Method: This was a cross-sectional mailed survey with a national sample of veterans with spinal cord injuries and disorders (n = 565), which included measures of demographics, perceived environmental barriers, participation, resilience, grief or loss, and self-efficacy. Data were analyzed using a latent variable path analysis; the model fit was assessed using χ2, normed χ2, root mean square error of approximation (RMSEA; <0.07), Comparative Fit Index (CFI; ≥0.95), and Tucker-Lewis Index (TLI; ≥0.95). Results: Participants were mostly male (93.9%), Caucasian or White (74.2%), and, on average, 62.4 years of age (SD = 10.48). Almost 62% had paraplegia, and 38.3% had a motor or sensory complete injury. The hypothesized model showed excellent fit, χ2(42) = 153.40, normed χ2 = 3.65, RMSEA = 0.07, CFI = 0.96, TLI = 0.95. To assess for full mediation, a direct path was added from environment to participation. This model showed nearly identical fit, χ2(41) = 153.39, normed χ2 = 3.74, RMSEA = 0.07, CFI = 0.96, TLI = 0.95; the path from environment to participation was not significant, unstandardized coefficient = −0.04, p = .92. Examination of indirect effects of the hypothesized model demonstrated that environment significantly influences participation through psychosocial factors, unstandardized coefficient = −4.85, p < .001. Together these results support full mediation. Conclusions: In conclusion the present study expands upon past research by suggesting that perceived environmental barriers play a role in internal factors, such as resilience and self-efficacy, which in turn influence participation. Interventions to improve environmental barriers may be warranted, but attention must also be paid to resilience, grief or loss, and self-efficacy to increase participation.