TARDEC researched head impact protective, energy attenuating materials for use in U.S. Army Ground System Vehicle (GSV) applications. The purpose of the project is to reduce potential head impact related mounted crew injuries and deaths which may occur during underbody blast, crash and rollover events. Commercial-off-the-shelf materials were evaluated for their energy attenuating performance. Exposed surface materials in combination with core material were also researched and evaluated. Baseline vehicle testing was conducted to understand the current head impact criterion. The results of this effort identified solutions which may potentially meet the needs of the Army to reduce head impact related injuries which may occur during crash, rollover and blast events. TARDEC used the knowledge gained from this project to create performance specification requirements for interior head impact protective components and materials for use in U.S. Army vehicles.