Five federal agencies may have spent $8.7 million leasing underutilized vehicles from the U. S. General Services Administration (GSA), according to a recent audit by the Government Accountability Office (GAO).

The GAO examined federal processes for assessing the utilization of vehicles federal agencies lease from the GSA. It studied five fleets and found that all of them had some percentage of vehicles that did not meet utilization criteria and did not have readily available justifications for keeping the vehicles.

The National Park Service topped the list with 47% of its vehicles falling in this category (costing $2.9 million), while on the other end, the National Aeronautics and Space Administration had 4% of its vehicles in this category (costing $0.1 million). The audit also evaluated the Air Force, Bureau of Indian Affairs, and the Veteran’s Health Administration.

“While costs paid to GSA may not equal cost savings associated with eliminating vehicles, without justifications and corrective actions, agencies could be spending millions of dollars on vehicles that may not be needed,” according to the audit.

Four of the agencies audited should ensure vehicles meet the utilization criteria or have a readily available justification document. Vehicles that are underutilized and unjustified should be reassigned or returned to the GSA, the audit found.

In another finding, the GSA fleet service representatives should better communicate with agency fleet managers and determine whether regulations should be amended to require that vehicle justifications are clearly documented and readily available.

Agencies mostly agreed with the recommendations and have either taken steps or plan to take steps to address the concerns brought up in the audit. In FY-2014, federal agencies spent $1.03 billion to lease 186,000 vehicles.