; 5 U.S.C. App.) and section 63145 of title 40, United States Code. (b) Subsection (a) shall not apply to Tribal contracts entered into by the Department of Housing and Urban Development with amounts made available under the headings Native American Programs and Native Hawaiian Housing Block Grant in this title. (c) The amounts provided by this section are designated by the Congress as being for an emergency requirement pursuant to section 251(b)(2)(A)(i) of the Balanced Budget and Emergency Deficit Control Act of 1985. 502. For amounts made available in this title under the headings Northeast Corridor Grants to the National Railroad Passenger Corporation and National Network Grants to the National Railroad Passenger Corporation , the Secretary of Transportation may not waive the requirements under section 24312 of title 49, United States Code, and section 24305(f) of title 49, United States Code: Provided, That for amounts made available in this title under such headings the Secretary shall require the National Railroad Passenger Corporation to comply with the Railroad Retirement Act of 1974 ( 45 U.S.C. 231 et seq.), the Railway Labor Act ( 45 U.S.C. 151 et seq.), and the Railroad Unemployment Insurance Act ( 45 U.S.C. 351 et seq.): Provided further, That the amounts made available in this title under such headings shall be used by the National Railroad Passenger Corporation to prevent employee furloughs: Provided further, That none of the funds made available in this title under such headings may be used by the National Railroad Passenger Corporation to reduce the frequency of rail service on any long-distance route or State-supported route (as such terms are defined in section 24102 of title 49, United States Code) below frequencies for such routes in fiscal year 2019, except in an emergency, during maintenance or construction outages impacting such routes, or at the request of the State or States supporting such State-supported routes. 503. None of the funds made available by this Act to the Department of