This project proposes to leverage the existing NCAA-DOD Concussion Assessment Research and Education (CARE) consortium research efforts at four U.S. Military Service Academies (MSAs) to examine in more detail the acute, intermediate, and long-term effects associated with concussion and/or repetitive head impact exposure on the health and military performance of Service Academy (SA) cadets/midshipmen. The proposed work will prospectively follow two cohorts of cadets and midshipmen over a four-year period: (1) those who sustained an mTBI while enrolled in a MSA; and (2) those who did not suffer an mTBI at a MSA (controls).