5 U.S.C. § 701 : US Code - Section 701: Application; definitions

      (a) This chapter applies, according to the provisions thereof,
    except to the extent that - 
        (1) statutes preclude judicial review; or
        (2) agency action is committed to agency discretion by law.

      (b) For the purpose of this chapter - 
        (1) "agency" means each authority of the Government of the
      United States, whether or not it is within or subject to review
      by another agency, but does not include - 
          (A) the Congress;
          (B) the courts of the United States;
          (C) the governments of the territories or possessions of the
        United States;
          (D) the government of the District of Columbia;
          (E) agencies composed of representatives of the parties or of
        representatives of organizations of the parties to the disputes
        determined by them;
          (F) courts martial and military commissions;
          (G) military authority exercised in the field in time of war
        or in occupied territory; or
          (H) functions conferred by sections 1738, 1739, 1743, and
        1744 of title 12; subchapter II of chapter 471 of title 49; or
        sections 1884, 1891-1902, and former section 1641(b)(2), of
        title 50, appendix; and

        (2) "person", "rule", "order", "license", "sanction", "relief",
      and "agency action" have the meanings given them by section 551
      of this title.