The Program Assessment Rating Tool (PART) was developed by the Office of Management and Budget to encourage agencies to develop program-specific performance measures and data in order to show program results. PART can be used to make funding recommendations in the President's budget proposals. Currently, only 6% of federal programs that have been PARTed have received a "results not demonstrated" rating, indicating that they lack performance measures and data. While this is a small percentage of overall outlays, it represents in some cases a large part of an agency's budget, indicating that a large portion of some agency activities and budgets are unable to show measurable results. However, the study also shows that over the three years of PART's existence, there has been measurable progress by agencies in moving above a "results not demonstrated" rating. This may indicate that agencies are responding to PART assessments by improving their measurements and data, that budget examiners are more experienced, or that a better set of programs is being evaluated each year. PART is only one variable in budgetary decision-making and while this study allows us to infer relationships between PART and funding decisions, it does not allow economists to determine if there is a relationship of causality.