Sec. 5. (a) This section applies to the following public pension or retirement funds:
(1) The public employees' retirement fund established under IC 5-10.2 and IC 5-10.3.
(2) The Indiana state teachers' retirement fund established under IC 5-10.2 and IC 5-10.4.
(3) The state excise police, gaming agent, gaming control officer, and conservation enforcement officers' retirement fund established under IC 5-10-5.5.
(4) The defined benefit plan of the legislators' retirement system established under IC 2-3.5-4.
(b) The board may not pay a postretirement benefit change or adjustment, including a postretirement benefit increase, thirteenth check, or other benefit change or adjustment granted by the general assembly after June 30, 2018, to members of a public pension or retirement fund listed in subsection (a), unless the change or adjustment is actuarially pre-funded.