CFR > Title 42 - Public Health > CHAPTER IV—CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES > SUBCHAPTER B—MEDICARE PROGRAM (parts 405 to 426) > PART 422—MEDICARE ADVANTAGE PROGRAM > SUBPART N—Medicare Contract Determinations and Appeals (§422.641 to §422.696) > 422.680—Witnesses.