In this paper, we describe work in performance standards for urban search and rescue (USAR) robots begun in 2004 by the Department of Homeland Security. This program is being coordinated by the National Institute of Standards and Technology and will result in consensus standards developed through ASTM International, under the Operational Equipment Subcommittee of their Homeland Security Committee. The first phase of the program involved definition of requirements by subject matter experts. Responders participated in a series of workshops to identify deployment categories for robots, performance categories, and ranges of acceptable or target performance in the various categories. Over one hundred individual requirements were identified, within main categories such as Human-System Interaction, Logistics, Operating Environment, and System (which includes Chassis, Communications, Mobility, Payload, Power, and Sensing). To ensure that the robot developers and eventual end users work closely together, "responders meet robots" events at situationally relevant sites are being held to refine and extend the performance requirements and develop standard test methods. The results of these standard performance tests will be captured in a compendium of existing and developmental robots with classifications and descriptors to differentiate particular robotic capabilities. This, along with ongoing efforts to categorize situational USAR constraints such as building collapse types or the presence of hazardous materials, will help responders match particular robotic capabilities to response needs. In general, these efforts will enable responders to effectively use robotic tools to enhance their effectiveness while reducing risk to personnel during disasters.