Objective: The current study sought to determine whether the Wechsler Test of Adult Reading (WTAR) provides a stable estimate of premorbid intellectual ability in acutely injured patients recovering from traumatic brain injury (TBI). Method: A total of 135 participants (43 mild TBI [mTBI], 40 moderate/severe TBI [msevTBI], 52 healthy controls) were administered the WTAR at 1 and 12 months post-injury. Results: Despite similar demographic profiles, participants with msevTBI performed significantly worse than controls on the WTAR at both time points. Moreover, the msevTBI group had a significant improvement in WTAR performance over the 1-year period. In contrast, those participants with mTBI did not significantly differ from healthy controls and both the mTBI and control groups demonstrated stability on the WTAR over time. Conclusions: Results indicate that word-reading tests may underestimate premorbid intelligence during the immediate recovery period for patients with msevTBI. Clinicians should consider alternative estimation measures in this TBI subpopulation.