Forty-percent of those contracts were subjected by federal agencies to competitive process with three or more proposals received, a number recommended by the Federal Acquisition Regulation, GAO said in a July report.
The Department of Health and Human Services used competitive procedures for most of its FSS orders but with only one or two more offers received, followed by the Defense Department and the General Services Administration, according to the report.
GAO noted in the report that adoption of the FSS program by federal agencies dropped by 19 percent to $25.7 billion in fiscal year 2014.
GAO also found that federal contracting officials do not regularly assess prices for goods and services purchased through the FSS program and fail to routinely ask for discounts from FSS prices.
GAO advised HHS, DoD and GSA to improve competition and price assessment through training improvements and release of new guidelines in order to raise awareness about the pricing rules stated in FAR.