The U.S. Army Test and Evaluation Command, or ATEC, is a unit of the United States Army Transformation and Training Command responsible for developmental testing, independent operational testing, independent evaluations, assessments, and experiments of Army equipment.

ATEC informs Army senior leaders of testing and evaluation activities. These activities help Army leadership make acquisition and fielding decisions.

ATEC has locations throughout the continental United States and Hawaii. ATEC headquarters is located at Aberdeen Proving Ground, Maryland.

On 18 November 1998, consolidation of existing Army (developmental and operational) testing commands was approved by the Vice Chief of Staff of the Army (VCSA).

The Operational Test and Evaluation Command (OPTEC) was redesignated as the Army Test and Evaluation Command (ATEC) on 1 October 1999.

All major subordinate commands of OPTEC were similarly redesignated:

ATEC employs approximately 9,000 military, civilian, and contract employees. These employees consist of test officers, engineers, scientists, technicians, researchers, and evaluators. ATEC is involved in over 2,300 tests annually, encompassing anything from individual weapons to National Missile Defense systems.

The annual budget for the command is in excess of half a billion dollars.^{[citation needed]}