Ninth grade is a critical juncture for students. Students who make a good transition to high school are likely to graduate within four years. Those who do not--who fail to earn as many credits as they should in ninth grade--face an elevated risk of dropping out of high school. To understand how well they are supporting ninth graders, more school districts are defining what students must have accomplished at the end of the first year of high school to be considered on track to graduation. In 2018, the School District of Philadelphia (SDP) established a new Ninth Grade On-Track Definition. To be considered on track to graduation, a student completing the first year of high school must have earned at least one credit in each core subject (English, mathematics, science, and social studies), plus one additional credit from any subject. Annually, the District expects to report the percentage of students on track to graduation at the end of ninth grade. In this report, the authors apply the 2018 Ninth Grade On-Track Definition to students who were first-time ninth graders in the SDP during the 2014-15 or 2015-16 school years. They examine how many students were on track to graduation, the characteristics of on-track and off-track students, and how on-track rates differ across high schools. Although the On-Track Definition was not in place at the time these students were in ninth grade, the analysis provides a benchmark against which progress can be measured and identifies characteristics of students and schools that might need additional support to start strong when they enter high school. This report also includes a set of questions that SDP educators and the community can ask to assess how students are supported in the ninth grade transition and what more could be done. [For an addendum to this report, see ED613891.]