28 U.S.C. § 2408: Security not required of United States

Security for damages or costs shall not be required of the United States, any department or agency thereof or any party acting under the direction of any such department or agency on the issuance of process or the institution or prosecution of any proceeding. Costs taxable, under other Acts of Congress, against the United States or any such department, agency or party shall be paid out of the contingent fund of the department or agency which directed the proceedings to be instituted.