The U.S. Small Business Administration (SBA or Agency) is modifying its method for calculating average annual receipts used to prescribe size standards for small businesses. Specifically, in accordance with the Small Business Runway Extension Act of 2018, SBA is changing its regulations on the calculation of average annual receipts for all of SBA's receipts-based size standards, and for other agencies' proposed receipts-based size standards, from a 3-year averaging period to a 5-year averaging period, outside of the SBA Business Loan and Disaster Loan Programs. SBA intends to seek comment on the Business Loan and Disaster Loan Programs in a proposed rule through a separate rulemaking. For all other programs, SBA adopts a transition period through January 6, 2022, during which firms may choose between using a 3-year averaging period and a 5-year averaging period.