This interim final rule contains amendments to the regulations governing the 8(a) Business Development (BD) program. The U.S. Small Business Administration (SBA) is revising its regulations to implement a provision in the Consolidated Appropriations Act, 2021 (Appropriations Act), and the National Defense Authorization Act for Fiscal Year 2021 (NDAA 2021), which authorized certain 8(a) Participants to extend their 8(a) BD program term by a period of one year. This interim final rule amends the 8(a) BD program regulations to carry out the changes made by the Act.