Special Guerrilla Unit Veterans Service Recognition Expansion Act of 2021 This bill expands eligibility for internment in national cemeteries to include certain individuals who the Department of Veterans Affairs determines served honorably with a special guerilla unit or irregular forces in Laos in support of the U.S. Armed Forces between February 28, 1961, and May 7, 1975. Such individuals are eligible if, at the time of their death, they resided in the United States and were a U.S. citizen or alien lawfully admitted for permanent residence in the United States.