C.F.R. » Title 42 » CHAPTER IV—CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES › SUBCHAPTER B—MEDICARE PROGRAM › PART 417—HEALTH MAINTENANCE ORGANIZATIONS, COMPETITIVE MEDICAL PLANS, AND HEALTH CARE PREPAYMENT PLANS › Subpart K—Enrollment, Entitlement, and Disenrollment under Medicare Contract