Abstract The increasing penetration of microgrids in appears to be part of a transition toward electricity distribution systems that are more decentralized than the current system. With microgrids gaining space as a competing and parallel distribution grid model and challenging the current centralized grid system, studying their adoption presents an opportunity to understand this socio-technical transition in the energy system. This study looks at this ongoing change in the United States and applies the Multi-Level Perspective framework to explore the drivers, contexts, processes, policies, institutions, and interactions that affect the adoption of microgrids. Through a qualitative case study analysis of California, New York, and Oregon, the study finds that natural disasters, massive power outages and climate change concerns have acted as key pressures for the adoption of microgrids. At the same time, the electric power system maintains important stabilization mechanisms, such as the availability of cheap and abundant electricity, as well a market structure that limits the opportunities of entry and profit for third-party developers, which make it harder for niche innovations like microgrids to break in. In addition, this study finds that state support in the form of funding and legislation is crucial for nurturing the microgrid niche market.