An agency may not procure new services under an existing GSA Schedule delivery order if the new services exceed scope of the original delivery order.
In a recent decision, Onix Networking Corp., B-411841 (Nov. 9, 2015), the GAO sustained a protest where the agency acquired a new type of software by modifying an existing delivery order for software license extensions because the acquisition exceeded the scope of the initial delivery order. According to the GAO, the out-of-scope modification amounted to an improper sole source contract.