31 C.F.R. § 223.16
A list of certificate holding companies is published annually as of August 1 in Department Circular No. 570, Companies Holding Certificates of Authority as Acceptable Sureties on Federal Bonds and as Acceptable Reinsuring Companies, with information as to underwriting limitations, areas in which listed sureties are licensed to transact surety business, and other details. If Treasury shall take any exceptions to the financial statements submitted by a company or other information pertinent to the company's financial solvency, before issuing Department Circular 570, Treasury shall give a company due notice of such exceptions. Copies of the Circular are available at https://www.fiscal.treasury.gov/surety-bonds/list-certified-companies.html, or from the Surety Bonds Program, upon request. Bonds underwritten by certified companies on the Department Circular No. 570 list may be presented to an agency bond-approving official for acceptance. Selection of a particular qualified company from among all companies holding certificates of authority is discretionary with the principal required to furnish the bond, but the acceptance of a bond by an agency bond-approving official is subject to § 223.17 .
31 C.F.R. §223.16