Brigade engineers conducted minefield and route clearance operations, road maintenance, road, airfield and base camp construction, and geospatial missions. The corps Staff Engineer Section supported combined and Joint Task Force 180 from June 2002 through May 2003 in Afghanistan.

In November 2004, the brigade headquarters deployed to Camp Victory, Iraq in support of OIF 04-06. The brigade grew to 6,100 personnel composed of three brigade headquarters, seven battalions, six separate companies and nine detachments. The brigade served as the Multi-National Corps-Iraq corps-level, engineer headquarters for all echelons-above-division engineers in Iraq, providing command and control for general support combat and construction engineer missions across the country. The brigade commander served simultaneously and the MNC-I C7 director of a 132-man coalition engineer section.

During this deployment, the brigade patrolled 57,950 kilometers of MSR Tampa for improvised explosive devices and unexploded explosive ordinances; expanded 14 bases in support of the MNC-I basing plan; emplaced or maintained 16 bridges; expanded detention capacity for 6,000 detainees; trained over 53,000 coalition soldiers on explosives hazards awareness; reduced over 11,000 caches and over 80,000 tons of explosive munitions; and provided geospatial support with more than 20,000 map products and nation-wide catalogued network of high-accuracy survey points.

In July 2007, the brigade headquarters deployed once again to Iraq, where it served at the MNC-I corps-level engineer headquarters, this time the brigade was based out of Joint Base Balad.

During this deployment, the 20th Eng. Bde. missions employed the principles of enabling counter insurgency operations by taking the fight to the enemy by repositioning engineer forces, creating unity of effort by nesting operations with maneuver units, and using engineer skill sets and staff capabilities to support lines of operations to reduce unemployment and improve civilian life.

During OIF 07-09, the brigade moved engineer units, task organized engineer forces as appropriate, and changed command and support relationships to create joint, multifunctional engineer battalions capable of conducting route clearance in support of division and BCT (in addition to  corps MSR/ASR) assured mobility missions, full-spectrum JSS/COP construction fully utilizing Air Force utilities detachment capabilities previously used for on-FOB construction, and supporting identified geographic areas for a more embedded, nested concept of support of maneuver units.

The 20th Eng. Bde. pioneered the use of disarmament, demobilization, and reintegration funding for Civil Service Corps through the Hawr Rajab Village of Hope CSC and Salah ad Din Road CSC, working with Joint Contraction Command Iraq/Afghanistan to write the first statements of work for training programs, which would later be used by MNC-I in a theater- wide effort.

On Sept. 16, 2009, the 20th Engineer Brigade transformed to a modular engineer unit losing its designation as combat and airborne. However, the brigade still retains the preponderance of the Army’s forcible entry echelon above brigade engineer force structure with two engineer battalions on airborne status and five dive companies. The brigade still retains the ability to employ the brigade assault command post in a forcible entry environment.

On Jan. 15, 2010, the brigade deployed the assault command post to Haiti in support of Operation Unified Response where they formed the core of the JTF-Haiti J7 (engineer staff) and facilitated structural assessments, developed the beddown plan for over 10,000 U.S. forces and conducted assessment of the ground lines of communications to facilitate the rapid distribution of aid.

In January 2011, the brigade headquarters, the 133rd Construction Management Team and the 326th Engineer Battalion deployed to Iraq in support of Operation New Dawn.

The brigade served as the sole engineer brigade in Iraq working directly for United States Forces Iraq. The brigade was based at Joint Base Balad and focused on counter improvised explosive device operations along theater-level main and alternate supply routes, bridging and military construction for troops units as well as the Department of Sate and the Office of Security Cooperation Iraq.

In June 2011, the brigade was given an additional mission to transition Contingency Operating Base Adder and all its property to the Government of Iraq. The brigade continued its mission as the theater-level engineer brigade, moved to COB Adder and assumed the duties and responsibilities and the base mayor of the 12,000 person base.

COB Adder was the last base transitioned in Iraq and in December 2011, the brigade redeployed to Fort Bragg.