Objective To examine the relations between time to rehabilitation after spinal cord injury (SCI) and rehabilitation outcomes at discharge and 1-year postinjury. Design Retrospective cohort study. Setting Facilities designated as Spinal Cord Injury Model Systems. Participants Patients (N=3937) experiencing traumatic SCI between 2000 and 2014, who were 18 years or older, and who were admitted to a model system within 24 hours of injury. Interventions Not applicable. Main Outcome Measures Rasch-transformed FIM motor score at discharge and 1-year postinjury, discharge to a private residence, and the Craig Handicap Assessment and Reporting Technique (CHART) Physical Independence and Mobility scores at 1-year postinjury. Results After accounting for health status, a 10% increase in time to rehabilitation was associated with a 1.50 lower FIM motor score at discharge (95% confidence interval [CI], −2.43 to −0.58; P=.001) and a 3.92 lower CHART Physical Independence score at 1-year postinjury (95% CI, −7.66 to −0.19; P=.04). Compared to the mean FIM motor score (37.5) and mean CHART Physical Independence score (74.7), the above-mentioned values represent relative declines of 4.0% and 5.3%, respectively. There was no association between time to rehabilitation and discharge to a private residence, 1-year FIM motor score, or the CHART mobility score. Conclusions Earlier rehabilitation after traumatic SCI may improve patients' functional status at discharge.