--- - |2+ Objective Analyze achievement trajectories of students who transfer out of their district of residence via Colorado's interdistrict open enrollment policy. Methods Drawing on a data set containing annual individual‐level records from the universe of students attending Colorado public schools between 2005–2006 and 2009–2010, we estimate the achievement trajectories of open enrollment participants via ordinary least squares (OLS) models containing student fixed effects. Results and Conclusion Our analyses indicate that the achievement of open enrollment participants gradually declines in the years leading up to their transfer. After open enrolling, students whose participation is stable through the duration they are observed in our data exhibit small achievement gains, but those who reenroll in their district of residence exhibit additional small declines. On average, those who use open enrollment as a long‐term education option tend to enroll in districts that are more advantaged on traditional measures of educational quality than their district of residence. - Social Science Quarterly, Volume 99, Issue 3, Page 1089-1104, September 2018.