Storing sufficient hydrogen on-board hydrogen-powered vehicles while meeting weight, volume, safety, cost, and other performance requirements is a significant technical challenge that is crucial to the success of hydrogen-fueled transportation. The current hydrogen storage targets set by the FreedomCAR and Fuel Partnership (a partnership between U.S. automobile companies, energy companies, and the DOE) will be reviewed and explained. Hydrogen storage system performance that has been measured thus far by the DOE Technology Validation program on prototype fuel cell vehicles that use pressurized hydrogen gas tanks will be described. The objectives and structure of the DOE’s National Hydrogen Storage Project to develop advanced material-based hydrogen storage systems will be presented, and progress achieved to date in the development of hydrogen storage materials summarized. Recent research results will be highlighted in the areas of theoretical guidance towards materials discovery, hydrogen adsorption in metal-organic frameworks and hydrogen spill-over effects, metal hydrides such as alane (AlH₃), organic liquids, and ammonia-borane compounds. The international collaborations currently in place on hydrogen storage will be summarized.