Ind. Code § 36-4-1-1 – Basis of classification

(a) Municipalities are classified according to their status and population as follows:
STATUS AND POPULATION CLASS
Cities of 600,000 or more First class cities
Cities of 35,000 to 599,999 Second class cities
Cities of less than 35,000 Third class cities
Other municipalities of any
population Towns
(b) Except as provided in subsection (c), a city that attains a population of thirty-five thousand (35,000) remains a second class city even though its population decreases to less than thirty-five thousand (35,000) at the next federal decennial census.
(c) The legislative body of a city to which subsection (b) applies may, by ordinance, adopt third class city status.
[Pre-Local Government Recodification Citations: 18-2-1-1; 18-2-1-1.5; 18-2-1-2 part; 18-3-2-1 part; 18-3-3-1 part.]
As added by Acts 1980, P.L.212, SEC.3. Amended by Acts 1981, P.L.44, SEC.37; P.L.340-1987, SEC.1; P.L.71-1997, SEC.2; P.L.64-2004, SEC.34; P.L.81-2004, SEC.46; P.L.119-2012, SEC.184.