Objective: To examine the impact of community-level social determinants of health (SDoH) on the onset of occupational therapy (OT) and physical therapy (PT) services among individuals hospitalized for traumatic brain injury (TBI). Setting: 14 acute care hospitals in the state of Colorado. Participants: We studied 5825 adults with TBI. Design: In a secondary analysis of de-identified electronic health record data, we performed multivariable logistic and linear regressions to calculate odds ratios (ORs) and 95% CIs for the likelihood of receiving services and duration to initiation of services among those who received them. Main Measures: Community-level SDoH, receipt of rehabilitation services, and onset of rehabilitation services. Results: Multivariable logistic and linear regressions revealed that those in top quartiles for community income were associated with duration to OT services, ranging from OR = 0.33 [05% CI, 0.07, 0.60] for quartile 2 to 0.76 [0.44, 1.08] for quartile 4 compared with those with the lowest quartile. Only the top quartile differed significantly for duration to PT services (0.63 [0.28, 0.98]). Relative to those with below the median community percentage of high school degree, those with above the median were associated with duration to PT services only (−0.32 [−0.60, −0.04]). Neither community percentage with bachelor's degree nor rural-urban designation was associated with duration to either therapy service. Conclusion: Further research is needed to determine whether our SDoH variables were too diffuse to capture individual experiences and impacts on care or whether community-level education and income, and rurality, truly do not influence time to therapy for patients hospitalized with TBI. Other, individual-level variables, such as age, comorbidity burden, and TBI severity, demonstrated clear relationships with therapy onset. These findings may help therapists evaluate and standardize equitable access to timely rehabilitation services. [ABSTRACT FROM AUTHOR]