Limited studies describe cognitive functioning in persons with multiple sclerosis (pwMS) across racial/ethnic groups, and none have explored the role of traumatic brain injury (TBI) (Amezcua et al., 2020; Petracca et al., 2023; Marrie et al., 2006). TBI can result in worse cognitive performance, including lower Symbol Digit Modalities Test scores (SDMT) (Landre et al., 2006). Rates of TBI are higher and cognitive outcomes worse for Black and Hispanic people residing in the United States (US) (Brenner et al., 2020). The MS Sunshine study previously showed that Black and Hispanic compared to White participants, both those with newly diagnosed MS and matched controls, had lower SDMT scores, which was not reflective of MS disease severity (Amezcua et al., 2020). Herein we build on these findings to examine whether differences in TBI and TBI severity could account for the lower SDMT scores in Black and Hispanic participants.