The USDA Forest Service Fire and Environmental Research Applications (FERA) Team, on behalf of the Joint Fire Sciences Program, is developing a system for characterizing fuels on managed and unmanaged wildland fuelbeds throughout the United States. The objective of the Fuels Characteristic Classification System is to provide users with detailed estimates of fuel characteristics and fire parameters to support fire hazard assessments, fuel treatment decisions, and to drive fire behavior and effects models and ecological assessments. Fuel Characteristic Classes are based on unique combinations of six fuelbed strata and 16 fuelbed categories. Fuelbed strata are vertical layers within a fuelbed and represent potentially independent combustion environments. Each stratum includes one or more fuelbed categories, which are based on their biological origin and have a distinct life history and response to disturbance. Within each fuelbed category, physiognomic classes are used to capture morphological, structural, and chemical features of its constituents and gradient variables are used to characterize size and relative abundance. By providing detailed information about the strata, categories, physiognomic classes and gradient variable thresholds the user may identify a specific fuel characteristic class for the fuelbed of interest. Alternately, the user may have more limited information available, such as cover type, a combination of fuelbed strata or categories, or remotely-sensed information such as vegetation physiognomy. Under these circumstances, an interface will be designed to predict the most appropriate fuel characteristic class.