BACKGROUND: Starting in 2015, the Center for Medicare and Medicaid Services (CMS) requires all Medicare providers to report quality measures through Physician Quality Reporting System (PQRS) or incur a 1.5 % financial penalty. Research indicates that physicians believe this reporting does not lead to high quality care; however, little research has examined what PQRS actually measures, which is reflective of the physicians and patient disease populations being assessed. OBJECTIVES: (1) Identify the proportion of measures that apply to different medical specialties, types of quality measurement, and National Quality Strategy (NQS) priorities. (2) One hundred and ninety-eight and 254 individual measures, respectively, were analyzed by three domains: medical specialty measured, type of measure, and NQS priority category. KEY RESULTS: Between 2011 and 2015, the type of measures changed significantly, with fewer processes (85.4 % vs. 66.5 %, p < 0.001) and more outcomes (12.6 % vs. 29.1 %, p < 0.001). The measures showed no significant specialty or NQS category differences. For subcategories within each specialty in 2015, differences in measure type were statistically significant: surgery had the highest percentage of outcomes (61.1 %) compared to 21.7 % of internal medicine and 5.9 % of obstetrics/gynecology. For NQS categories, internal medicine had the highest percentage of effective clinical care measures (68.5 %), compared to 22.2 % in surgery. Surgery had the highest percentage of patient safety (31.9 %) and communication and care coordination measures (27.8 %) compared with internal medicine (5.4 % and 6.5 %). CONCLUSIONS: Our study shows that PQRS measures include many medical specialties and significantly more outcomes in recent years, particularly for surgery. PQRS still lacks sufficient measures for half of NQS priorities and sufficient outcomes to assess internal medicine and obstetrics/gynecology. CMS must continue to improve PQRS measures to better assess and encourage highquality care for all Americans.KEY WORDS: medicare; quality assessment; quality improvement; performance measurement; healthy policy.