Section 5323(m) of title 49, United States Code, directs FTA to issue regulations requiring pre-award and post-delivery audits when a recipient of Federal financial assistance purchases rolling stock with funds made available under chapter 53 of title 49. On July 31, 2024, the DOT Office of the Inspector General (OIG) issued a report titled "FTA’s Oversight of SEPTA’s Compliance With Buy America Rolling Stock Requirements Faced Several Challenges" made eight recommendations for FTA to improve its oversight of compliance with Buy America rolling stock requirements. Three of the eight recommendations called for FTA to initiate actions to update existing requirements for pre-award and post-delivery audits. Accordingly, through this rulemaking, FTA proposes to update part 663 of title 49, Code of Federal Regulations, to: (1) require supplier certificates from all component suppliers, which is currently recommended but not required by FTA guidance; (2) require recipients/auditors to maintain audit documentation; and (3) require recipients/auditors to certify that they have reviewed all component supplier certificates for accuracy.