The amount representing profit, gain or income derived from a contract, or contracts, with the United States or any department, agency or instrumentality thereof, or from any subcontractor, or subcontracts thereunder subsequently repaid to the United States or any department, agency or instrumentality thereof, pursuant to renegotiation or repricing under the laws of the United States shall not be included in gross income and shall be exempt from taxation under this Chapter.
La. Revenue and Taxation § 47:50