Amends the Contractor Prompt Payment Act. Provides that a public construction contract may provide for the withholding of retainage of up to 5% (rather than 10%) of any payment made prior to the completion of 50% of the contract. Provides that when a contract is 50% complete, retainage withheld shall be reduced so that no more than 1% (rather than 5%) is held. Provides that after the contract is 50% complete, no more than 1% (rather than 5%) of the amount of any subsequent payments made under the contract may be held as retainage.