Section 13-351. Method of computing retirement allowance of chief of department

a. Any member who shall have been appointed as  a  chief  of  department of the fire department shall be entitled, upon retirement for
  service  from  such  position, to elect to receive, in lieu of any other
  service retirement benefit to which he  or  she  may  be  entitled,  the
  applicable   retirement   allowance   provided  for  in  the  succeeding
  subdivisions of this section.
    b. If such member was an original plan member not subject  to  article
  eleven  (as  defined  in  subdivision  four-c  of section 13-313 of this
  subchapter) at the time of such retirement,  such  retirement  allowance
  shall  be  equal  to  two-thirds  of  his  or  her  salary  as  chief of
  department.
    c. If such member was an improved benefits plan member not subject  to
  article eleven (as defined in subdivision four-i of such section 13-313)
  at  the time of such retirement, such retirement allowance shall consist
  of  an  annuity  which  is  the  actuarial  equivalent  of  his  or  her
  accumulated  deductions  at  the  time of such retirement and a pension,
  which, when added to such annuity, will make such  retirement  allowance
  equal to two-thirds of his or her salary as chief of department. For the
  purpose  of  computing the annuity portion of such retirement allowance,
  his or her accumulated deductions shall be the required amount  of  such
  deductions  at  the  time  of  his or her retirement from such position,
  including any amount then remaining unpaid with respect to  his  or  her
  contribution  rate  deficiency  (as defined in subdivision twenty-one of
  such section) 13-313, if any, without any increase resulting from excess
  contributions and  without  any  decrease  resulting  from  withdrawals,
  loans,  optional  modification,  payment of his or her contributions for
  old age and survivor's insurance coverage, or from any other transaction
  authorized by law. For the purposes of  this  subdivision  c,  any  such
  unpaid  amount  of contribution rate deficiency, in the case of any such
  member who becomes an improved benefits plan member before completion of
  his or her minimum period for service retirement,  shall  be  deemed  to
  consist  of  such  amount  plus regular interest thereon from his or her
  date of commencement of  contributions  as  an  improved  benefits  plan
  member  (as  defined  in subdivision nineteen of such section) 13-313 to
  the date of  completion  of  his  or  her  minimum  period  for  service
  retirement.
    d.  If  such  member  was  an  original plan member subject to article
  eleven (as defined in subdivision four-d of such section 13-313) at  the
  time  of  such retirement, such retirement allowance shall be determined
  pursuant to the provisions of subdivision b of this section,  except  to
  the  extent  and  in  the  manner that any such provision is modified by
  article eleven.
    e. If such member was an improved  benefits  plan  member  subject  to
  article eleven (as defined in subdivision four-j of such section) 13-313
  at  the  time  of  such  retirement,  such retirement allowance shall be
  determined pursuant to the provisions of subdivision c of this  section,
  except  to  the  extent  and  in  the  manner that any such provision is
  modified by article eleven.