This report analyzes changes in academic performance as measured by test scores and graduation rates in the Denver Public Schools versus comparable schools in Colorado over 11 years of the district’s experimenting with the “portfolio” approach to school district management. This approach includes central-office oversight of different school types (such as charter schools, innovation schools, and district-run schools), with widespread parental choice under a single enrollment system. The reported academic gains are dramatic and worth drawing attention to, but attributing them specifically to the portfolio reforms seems premature and thus not useful in showing how other districts could replicate that success.