42 C.F.R. § 422.110
Discrimination against beneficiaries prohibited
(a) General prohibition. Except as provided in paragraph (b) of this section, an MA organization may not deny, limit, or condition the coverage or furnishing of benefits to individuals eligible to enroll in an MA plan offered by the organization on the basis of any factor that is related to health status, including, but not limited to the following:
(1) Medical condition, including mental as well as physical illness.
(2) Claims experience.
(3) Receipt of health care.
(4) Medical history.
(5) Genetic information.
(6) Evidence of insurability, including conditions arising out of acts of domestic violence.
(7) Disability.
(b) Exception. For coverage before January 1, 2021, an MA organization may not enroll an individual who has been medically determined to have end-stage renal disease. However, an enrollee who develops end-stage renal disease while enrolled in a particular MA organization may not be disenrolled for that reason. An individual who is an enrollee of a particular MA organization, and who resides in the MA plan service area at the time he or she first becomes MA eligible, or, an individual enrolled by an MA organization that allows those who reside outside its MA service area to enroll in an MA plan as set forth at § 422.50(a)(3)(ii), then that individual is considered to be “enrolled” in the MA organization for purposes of the preceding sentence.