Standalone programs are those that have a single teacher who is responsible for all classes within the program. This qualitative case study was intended to explore the perceptions and reactions of teachers of standalone programs on self-selected online professional development. In this study, andragogy, the study of adult learning, provided the theoretical framework. The problem was the lack of professional development with relevant content, collaboration, and supports for teachers of standalone programs. Guidance for this research study came from three research questions. The sample for this study was nine teachers of standalone programs from a mid-western suburban school district. Zoom software was used to collect using individual semi-structured interviews and a focus group. Once the data were collected, the thematic analysis approach was applied to reveal four themes. The findings suggested that teachers need (a) autonomy and choice, (b) group representation during professional development sessions, (c) collaboration before, during, and after professional development, and (d) ongoing access to knowledge when considering self-selected online professional development. The implications of the findings are that there is a lack of professional development with these characteristics. Teachers of standalone programs self-selected online professional development, but these online professional development sessions did not meet all the needs of teachers of standalone programs. Recommendations for future practice is that development of professional development should include individual professional development plans, create professional development design committees that include teachers of standalone programs, and should continuously evaluate the needs of teachers of standalone programs. Recommendations for future research should be expanded to include school administrators, a focus on the individual themes of this study, and the perceptions and reactions of teachers of standalone programs on informal learning. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]