Given the urgency of development problems world-wide, as well as the opportunities of open source appropriate technology (OSAT) to help expedite sustainable development goals, a better understanding of the barriers limiting the scaling of OSAT is needed. In this study, key organizations and researchers working in the field of appropriate technology (AT) were interviewed to identify barriers to OSAT. The data was analyzed via pattern coding and content analysis. Results reveal that among the most pressing problems for those working in the field of AT were the need for better communication and collaboration between the agencies and communities to share the knowledge and resources, and to work in partnership. Specific barriers include: i) AT seen as inferior or “poor person's” technology, ii) technical transferability and robustness of AT, iii) insufficient funding, iv) weak institutional support, and v) the challenges of distance and time in tackling rural poverty. Finally, future work is outlined to better understand and overcome these barriers.