Okla. Stat. tit. 19, § 19-8

A. Any public works contract shall provide for partial payment

based upon work completed. The contract shall provide that up to

ten percent (10%) of all such partial payments made shall be

withheld as retainage. At any time the contractor has completed in

excess of fifty percent (50%) of the total contract amount, the

retainage shall be reduced to not less than five percent (5%) of the

amount earned to date if the owner or owner's duly authorized

representative has determined that satisfactory progress is being

made, and upon approval by the surety. The amount retained shall be

sufficient to ensure payment of:

1. Any taxes due the State of Oklahoma;

2. Personal property taxes or any municipal sales taxes due on

the contractor's equipment and supplies;

3. Any workers compensation coverage; and

4. Any amount due and owing to any subcontractor who furnished

any material or equipment to the contractor or performed any labor

as a subcontractor, or as an artisan or day laborer in the employ of

the contractor.

B. For purposes of this section a public works contract means a

contract between a county of this state and a contractor for the

construction, alteration, repair, improvement, moving, wrecking or

demolition of any highway, road, railroad, earthwork, building or

other structure, project, development or improvement, whether it be

in whole or in part. The provisions of this section shall not apply

to railroad companies operating in this state.