This study is the first in-depth look at Chicago's charter schools by the University of Chicago Consortium on School Research (UChicago Consortium). The authors examined four key dimensions of charter high schools in Chicago Public Schools (CPS): (1) school organization and policies; (2) incoming skills and characteristics of charter high school enrollees; (3) school transfers; and (4) student performance. The study relied primarily on data from 2010, 2011, 2012, and 2013. Analyses of charter schools' organizational capacity examined teacher and student survey responses from these years. Analyses of students' incoming skills and characteristics, school transfers, and high school outcomes were based on students who were first-time ninth-graders in each of these years. Key findings include: (1) On average, CPS charter high schools looked similar to non-charter, non-selective schools on some dimensions of organizational capacity, such as leadership, but they looked quite different on other dimensions, such as instruction and preparation of students for the future; (2) Most CPS charter high schools enrolled students whose eighth-grade test scores were similar to or lower than students in non-charter high schools who came from their same neighborhoods and elementary schools, but whose eighth-grade attendance was higher; (3) Students who enrolled in a charter high school in ninth grade were more likely to transfer to another CPS high school than students enrolled in a non-charter high school, even after taking into account differences in incoming skills, experiences, and characteristics; (4) On average, charter school students performed better on some (but not all) high school outcomes than students enrolled in non-charter high schools, controlling for differences in incoming skills, experiences, and background characteristics; (5) On average, charter school students' performance on post-secondary outcomes was much higher than similar students who attended non-charter high schools; and (6) There was substantial variation among charter schools on key student outcomes, including test scores, college enrollment, and college selectivity. [Additional support was provided by the Consortium Investor Council.]