Measuring What Matters Act This bill establishes a working group—the U.S. Commission on Reforming Police Metrics—to study best practices for measuring public trust in police institutions and including such findings in police performance measurement. The working group must report on its findings and conclusions, including recommendations. The bill requires the Department of Justice to establish a pilot program to award competitive grants for technical assistance and financial support to local police departments and sheriff departments that carry out the recommendations of the working group.