48 CFR §845.402-70

1. (a)For other than firm-fixed-price contracts, contractor-acquired property items not anticipated at time of contract award, or not otherwise specified for delivery on an existing line item, shall, by means of a contract modification, be specified for delivery to the Government on an added contract line item. The value of such contractor-acquired property item shall be recorded at the original purchase cost. Unless otherwise noted by the contractor at the time of delivery to the Government, the placed-in-service date shall be the date of acquisition or completed manufacture, if fabricated.
2. (b)Following delivery and acceptance by the Government of contractor-acquired property items, if these items are to be retained by the contractor for continued use under a successor contract, these items become Government-furnished property (GFP). The items shall be added to the successor contract as GFP by contract modification.
3. (c)Individual contractor-acquired property items should be recorded in the contractor's property management system at the contractor's original purchase cost.
4. (d)All other contractor inventory that is excess to the needs of the contract shall be disposed of in accordance with FAR subpart 45.6.