Benchmarking of cost efficiency has growing use in energy utility regulation. The state of the art has been limited in many countries by the small size of available national data sets and poor data on capital cost. Data available in the United States place fewer constraints on benchmarking methods. This paper develops an econometric cost benchmarking model for power distribution that is based on U.S. data. The model can address total cost and its major components. Numerous cost drivers are identified. Statistical tests of efficiency hypotheses are performed. The cost performances of utilities are compared to the industry norm. The suitability of the alternative frontier standard in regulatory applications is discussed.