Ga. Code § 13-10-60
Except as otherwise provided in Title 32, payment bonds shall be required for all state public works construction contracts with an estimated contract amount greater than $100,000.00; provided, however, that the state may require a payment bond for public works construction contracts that are estimated at $100,000.00 or less. No public works construction contract requiring a payment bond shall be valid for any purpose unless the contractor gives such payment bond; provided, however, that in lieu of such payment bond, the state, in its discretion, may accept a cashier's check, certified check, or cash for the use and protection of all subcontractors and all persons supplying labor, materials, machinery, and equipment in the prosecution of work provided in the contract. The payment bond or other security accepted in lieu of a payment bond shall be in the amount of at least the total amount payable by the terms of the initial contract and shall be increased if requested by the state as the contract amount is increased.
OCGA § 13-10-60