CFR›Title 42›Chapter IV›Part 400 ContainsSubparts A–CCorpusDaily eCFRDisplayed edition2026-04-15Last updated2026-04-15 PART 400—INTRODUCTION; DEFINITIONS Subparts A Subpart A [Reserved] B Subpart B—Definitions Sections 400.200–400.203 C Subpart C [Reserved] Authority42 U.S.C. 1302 and 1395hh and 44 U.S.C. Chapter 35. Next 401 Part 401—General Administrative Requirements