The previous research on goal ambiguity has suggested some methodological issues, such as the lack of a clear concept of program goal ambiguity, the use of single-dimension goal ambiguity, the exclusive dependence on perceptual data, and the lack of large-sample empirical studies. Recognizing these issues and identifying goal components or contents (target, time limit, and external evaluation) of goal-setting theory and of the program goal system in the Program Assessment Rating Tool (PART) of the U.S. federal government, this study conceptualizes program goal ambiguity and its three subdimensions: target-specification goal ambiguity, time-specification goal ambiguity, and program evaluation goal ambiguity. In addition, this study develops the objective measures of the three new dimensions of program goal ambiguity and then provides the empirical evidence of the construct validity, including the convergent and discriminant validity, and reliability of the three new measures. The intention of this study is to develop a means to empirically demonstrate goal ambiguity in the U.S. federal programs and, furthermore, build a foundation for the future research related to program goal ambiguity in public administration. To this purpose, the current research focuses on the U.S. federal programs, using a sample consisting of 767 programs.