Major General Timothy L. Rieger, was appointed as the Acting Vice Chief of the National Guard Bureau, Arlington, Virginia on 1 November 2024. The VCNGB is second in charge of the National Guard Bureau which is a joint activity of the Department of Defense. The VCNGB assists the Chief of the National Guard Bureau in performing duties as a member of the Joint Chiefs of Staff and principal advisor to the Secretary of Defense, Chairman of the Joint Chiefs of Staff, Secretary of the Army, and Secretary of the Air Force. The Vice Chief also serves as the principal advisor to the Secretary of the Army, Secretary of the Air Force, the Chief of Staff of the Army, and the Chief of Staff of the Air Force, on matters relating to federalized forces of the Guard and its subcomponents, the Army National Guard of the United States, and the Air National Guard of the United States. 

Prior to his current assignment, he served as Principal Deputy General Counsel, National Guard Bureau, Washington, DC.

MG Rieger received a Bachelor of Arts degree in Political Science from the University of California, Los Angeles and a Juris Doctor from the University of the Pacific. He has served in the Judge Advocate General Corps as a Staff Judge Advocate, Command Judge Advocate, State Staff Judge Advocate, and Chief, Army National Guard Trial Defense Service. He served as the Assistant Adjutant General, California National Guard from 2018 to 2022.

MG Rieger is a retired Peace Officer, Attorney, and State Executive whose 26 years of service to California include serving as Deputy District Attorney, Sacramento County, Deputy Attorney General, Deputy Director of the Department of Justice, Deputy Cabinet Secretary, and several other Gubernatorial appointments.

His awards and decorations include the Army Distinguished Service Medal, Legion of Merit, Bronze Star Medal, Combat Action Badge, and the Army Staff Identification Badge.  

MG Rieger and his wife Regina have two children and three grandchildren.