The organization of the 16th Infantry Regiment has undergone numerous changes over the past 150 years. It remained under various regimental tables of organization and equipment (TOE) from 1861 until 1957 when the U.S. Army adopted the Combat Arms Regimental System (CARS). At that point, the true regimental structure was abandoned by the Army in favor of what termed a “battle group.” Commonly referred to as the “Pentomic” organization for the five battle groups in each division, the battle group was designed for the atomic battlefield, but the concept only survived about seven years, and even less in the Reserve Components.

During the Pentomic era, the battle group TOE underwent some refinement, but within a relatively short period, the Army decided that the battle group structure itself was too unwieldy. Therefore, the Reorganization of the Army Division (ROAD) structure was implemented in 1963 and at that point all elements of the 16th Infantry were reorganized into battalions. Since 1963, the battalions of the 16th Infantry have undergone numerous organizational changes. The major changes to the regimental, battle group, and battalion TOEs are illustrated in the links to the right.