A new transit business model, microtransit, with inclusion of technology innovations is emerging in the market. Given its potential to address the equity, accessibility, and environmental needs of the public, public transportation agencies are experimenting with real-life models of this service to fill gaps in traditional transit in the US. However, why some people are interested in microtransit while other are not, remains an open question. What factors could strengthen or discourage a microtransit adopter to continue to use it? Who are these early adopters of microtransit? Previous literature has explored limited factors that influence microtransit ridership, such as availability and accessibility, wait time, app, and booking system. Guided by the theory of planned behavior, this study aims to fill the gap by conducting a large-scale survey focus on microtransit adopters and other means of transportation users in the Sacramento area of California in 2021 to address these research questions. The results will help transportation planners better understand important factors that influence the adoption and use of microtransit, and thereby make well-informed decisions to encourage this new business model in the future.