Section 13-215. Membership; composition and eligibility

a. The membership of the pension fund shall consist of:
    (1)  all  persons  in  city-service, as defined in this subchapter, in
  positions in the competitive class of the civil service, who shall serve
  probationary periods, or who shall receive permanent appointments in the
  police force after the time when this section shall take effect; and
    (2) all persons in city-service, as defined in  this  subchapter,  who
  hold  a  position of surgeon of police classified in the non-competitive
  class of the civil service.
    b. Notwithstanding any other provision of this subchapter or any other
  law to the contrary, in any case where  a  member  who  is  eligible  to
  retire  for  service is appointed police commissioner or a deputy police
  commissioner, he or she shall, while serving as police  commissioner  or
  deputy police commissioner, continue to be a member of the pension fund.
  For  the  purposes  of  this  subchapter,  a  member  serving  as police
  commissioner or deputy police commissioner whose membership is continued
  pursuant to this subdivision b or whose membership is restored  pursuant
  to  subdivision a of section 13-262 of this subchapter shall, during the
  period of such continuance or restoration of membership, be deemed to be
  a member of the police force in the department and his or her service as
  police commissioner or deputy police  commissioner  during  such  period
  shall be deemed to be service in such force.