Okla. Stat. tit. 61, § 61-113.1v2: Partial payment - Retainage

A. A public construction contract shall provide for partial

payment based upon work completed. The contract shall provide that

up to five percent (5%) of all 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 two and one-half percent (2.5%) of the

amount earned to date once the public agency has determined that

satisfactory progress is being made.

B. The Department of Transportation or the Oklahoma Turnpike

Authority shall not withhold retainage on public construction

contracts awarded by the Department or the Authority.

C. The Department of Transportation shall not withhold

retainage or require any bond on projects awarded to railroads on

the railroad's privately owned or operated rail property.