In 1920, the 5th Pioneer Infantry (Engineers) was re-designated the 101st Engineer Battalion and realigned under the 26th Yankee Division, where it would remain until the division was deactivated in 1993.
The 101st Engineer Battalion fought with the 26th Infantry Division under Patton's Third Army, and provided the maps to the Third Army for the relief of the 101st Airborne Division during the Battle of the Bulge.
From 1993 to 2006 the 101st Engineer Battalion was aligned under the 42nd Infantry Division.
In 2006, HHC deployed to Kosovo as part of Task Force Falcon.
In October 2008, the Battalion was placed under the new 26th Maneuver Enhancement Brigade, and placed the "YD" patch back on its left shoulder.
In June 2009 the Battalion mobilized for Operation Iraqi Freedom, providing Construction and Combat Engineer support to the Multi-National Division Baghdad/United States Division-Central area. For this, the Battalion earned a Meritorious Unit Commendation ribbon.
