In this interpretative phenomenological analysis (IPA) study, we found that the experiences of online teachers are highly complex and individualized, and that the development of their concerns as teachers is largely unaffected by years of teaching experience. Because of the dramatic increase in online K-12 education, there is a need for additional research to understand evidence-based practices in online teaching. Few studies have attempted to capture the rich experience of online teachers through a careful analysis of their teaching concerns. In this study, educators from a large online K-12 institution were contacted via email and invited to participate. Final study participants were purposely selected to represent both new and experienced educators in order to understand the possible impact of teaching experience on the development of concerns. In total, seven educators were chosen to participate in two online video interviews and bimonthly journaling entries over a four-month period of time. These educators revealed numerous teaching-related concerns hereafter categorized by personal, instructional, and relational themes, along with categories found at the intersection of these three themes. The findings presented here encourage greater dialogue between teachers and organizational leaders to understand and mitigate the negative impact of these concerns.