As used in this subpart-
First-tier subcontract means a subcontract awarded directly by the contractor for the purpose of acquiring services for performance of a prime contract. It does not include the contractor's supplier agreements with vendors, such as long-term arrangements for materials or supplies or services that benefit multiple contracts and/or the costs of which are normally applied to a contractor's general and administrative expenses or indirect costs.
48 C.F.R. §204.1701