Indiana Code Title 36. Local Government § 36-1-12-17

Sec. 17. (a) A contract for road or street work must contain a provision for the timely payment of claims made by the contractor.

(b) Each contract must provide for final payment within one hundred twenty (120) days after final acceptance and completion of the contract.  Final payment may not be made on any amount that is in dispute, but final payment may be made on that part of a contract or those amounts that are not in dispute.

(c) For each day after one hundred twenty (120) days, the board shall pay to the contractor interest for late payment of money due to the contractor.  However, interest may not be paid for those days that the delay in payment is not directly attributable to the board.  The annual percentage rate of interest that the board shall pay on the unpaid balance is twelve percent (12%).