National Capital region
(3) National capital region .— The term “National Capital region” means— (A) the District of Columbia; (B) Montgomery and Prince Georges Counties in Maryland; (C) Arlington, Fairfax, Loudoun, and Prince William Counties in Virginia; and (D) all cities in Maryland or Virginia in the geographic area bounded by the outer boundaries of the combined area of the counties listed in subparagraphs (B) and (C).