Purpose: To compare recovery experienced during inpatient rehabilitation among individuals with traumatic brain injury (TBI) based on whether their acute care included the Clinical Institute Withdrawal Assessment for Alcohol (CIWA) protocol. Design: Participants included 234 individuals with TBI who completed inpatient rehabilitation at a TBI Model Systems site. Of these, 67 patients were treated using the CIWA protocol (TBI + CIWA); 167 patients were treated for TBI alone (TBI only). Demographic, injury, and treatment variables between the 2 groups were compared. A repeated-measures analysis of variance (ANOVA) compared Disability Rating Scale (DRS) scores between the groups at admission and discharge from inpatient rehabilitation. Results: The 2 groups did not significantly differ on DRS scores at admission to inpatient rehabilitation: TBI + CIWA, M = 9.6 (SD = 3.5) vs. TBI only, M = 10.1 (SD = 4.2). There was a significant difference in DRS scores at discharge, with the TBI + CIWA group having lower scores: TBI + CIWA, M = 6.4 (SD = 1.9) vs. TBI only, M = 7.0 (SD = 2.2). A repeated-measures ANOVA of DRS scores from admission to discharge revealed a significant between-subjects effect based on patients’ Mississippi categorization of posttraumatic amnesia (PTA) duration (p < .001) and age (p = .016) but not based on their CIWA status (p = .068). A post hoc comparison including age as a covariate revealed a significant difference based on CIWA status (p = .013) within the “moderate” injury group at discharge, with the TBI + CIWA group having lower discharge DRS scores. Conclusions: Given the significant symptom overlap between alcohol withdrawal and PTA, it is likely that these 2 delirium presentations are confounded during the initial recovery from TBI, leading to “overestimation” of injury severity—particularly among individuals with moderate TBI.