48 CFR 28.201: 28.201 Requirements for security.

(a) Agencies shall obtain adequate security for bonds (including coinsurance and reinsurance agreements) required or used with a contract for supplies or services (including construction). Acceptable forms of security include (1) corporate or individual sureties or (2) any of the types of security authorized in lieu of sureties by 28.204.

(b) Solicitations shall not preclude offerors from using the types of surety or other security permitted by this subpart, unless prohibited by law or regulation.