30 CFR §735.22

The agency shall arrange for an independent audit no less frequently than once every two years, pursuant to the requirements of Office of Management and Budget Circular No. A-102, Attachment P. The audits will be performed in accordance with the “Standards for Audit of Governmental Organizations, Programs, Activities, and Functions” and the “Guidelines for Financial and Compliance Audits of Federally Assisted Programs” published by the Comptroller General of the United States and guidance provided by the cognizant Federal audit agency.