As K-12 online programs mature, it is increasingly important that they work to retain their effective teachers. However, there is little research that has examined teacher satisfaction in K-12 online learning environments. Our analysis of 22 interviews with 11 teachers at an online charter school identified three primary factors that influenced teacher satisfaction. First, teachers enjoyed having flexibility in when, where, and how they taught. The use of open educational resources was especially important because it enabled teachers to make modifications to meet student needs. Second, teachers were most satisfied when they were provided with time to interact individually with students. Third, teachers appeared most satisfied when their efforts positively impacted student performance. Similarly, teachers appreciated administrative support that increased teachers' capacity to impact student performance. We also discuss possible tensions that school administrators may experience as they attempt to balance these factors with other--sometimes competing--forces.