Indiana Code Title 5. State and Local Administration § 5-1.2-6-7

Sec. 7. If the cost of a contract for construction or for the purchase of equipment, materials, or supplies involves an expenditure of more than twenty thousand dollars ($20,000), the authority shall make a written contract with the lowest and best bidder after advertisement for not less than two (2) consecutive weeks in a newspaper of general circulation in Marion County, Indiana, and in other publications if the authority determines appropriate. The notice must state the general character of the work and the general character of the materials to be furnished, the place where the plans and specifications may be examined, and the time and place for receiving bids.  Each bid must contain the full name of every person or company interested in the bid and must be accompanied by a sufficient bond or certified check on a solvent bank so that if the bid is accepted, a contract will be entered into and the performance of the bidder's proposal secured.  The authority may reject any and all bids.  A bond with good and sufficient surety approved by the authority is required of all contractors in an amount equal to at least fifty percent (50%) of the contract price conditioned upon the faithful performance of the contract.