Indiana Code Title 5. State and Local Administration § 5-22-20-2

(1) By agreement on a fixed price adjustment before the beginning of the pertinent performance or as soon after the beginning of the performance as practicable.

(2) By unit prices specified in the contract or subsequently agreed upon.

(3) By the costs attributable to the events or situations under such clauses with adjustment of profit or fee, all as specified in the contract or subsequently agreed upon.

(4) In such other manner as the contracting parties may mutually agree.

(5) In the absence of agreements by the parties, by a unilateral determination by the governmental body of the costs attributable to the events or situations under such clauses, with adjustment of profit or fee, all as computed by the governmental body in accordance with applicable rules adopted by the governmental body.