Kan. Stat. § 13-1498
The governing body of any city operating under the provisions of this act may at any time it desires to do so, retire any elective or appointive officer or employee, other than members of the police department, fire department, water and light department, and all day laborers not paid on a monthly basis and any officer or employee who elects not to come under the provisions of this act, after such elective or appointive officer or employee has reached the age of sixty (60) years, and has served the city for an aggregate of twenty (20) years or more.
Upon such retirement the governing body shall pay semimonthly to such elective or appointive officer or employee, so retired, a sum equal to fifty percent (50%) of the average salary or wages such elective or appointive officer or employee was receiving during the two-year period immediately preceding the date of his or her retirement except as provided in K.S.A. 13-1499a: Provided, That for the purpose of computing a pension the maximum salaries of the mayor and commissioners shall be regarded as those provided by section 13-1804 of the General Statutes Supplement of 1953 irrespective of any subsequent increases as may be provided by law.
K.S.A. 13-1498