In today's environment of rapidly evolving conflicts, the Army's goal is to have units that have the combat power of heavy units but that can be transported anywhere in the world in a matter of days. To address concerns about the armored vehicle fleet's aging and the difficulties involved in transporting it as well as to equip the Army more suitably to conduct operations overseas on short notice using forces based in the United States the service created the Future Combat Systems (FCS) program in 2000. A major modernization effort, the program is designed in part to develop and purchase vehicles to replace those now in the heavy forces; the new vehicles would be much lighter, thereby easing the deployment of units equipped with them. In the analysis presented in this report, the Congressional Budget Office (CBO) examined the current status of the Army's fleet of armored vehicles and assessed the speed of deployment of the service's heavy forces. It also evaluated the FCS program, considering the program's costs as well as its advantages and disadvantages and comparing it with several alternative plans for modernizing the Army's heavy forces.