The chief of staff identified the 3d Infantry Division, scheduled to return to Iraq in early 2005, as the first formation to change to a modular structure. He also directed that normal force development methods not be used. Instead, an ad hoc group, Task Force Modularity, would draw up the modular force plans. By the time the task force disbanded in February 2005, most of the major design decisions for the modular force had been made and modular brigade combat teams of the 3d Infantry Division had deployed to Iraq. This account of designing the modular force highlights a critical part of the Army’s program to prepare itself for an increasingly turbulent world and illustrates the intellectual and organizational resources the service can call on in that effort.