•Predictors of COVID-19 vaccine uptake intentions both under regular circumstances as well as under EUA included high perceived susceptibility to COVID-19, high perceived benefits of the vaccine, and scoring low on barriers to the vaccine.•Predictors of COVID-19 vaccine uptake under EUA also included age and race/ethnicity.•Concerns about rushed vaccine development appear to reduce vaccine uptake intent, as well as willingness to get the vaccine under EUA. This study assessed psychosocial predictors of U.S. adults’ willingness to get a future COVID-19 vaccine and whether these predictors differ under an emergency use authorization (EUA) release of the vaccine. A survey of 788 U.S. adults was conducted to explore the relationships between demographics and psychosocial predictors of intent to get a future COVID-19 vaccine as well as willingness to get such a vaccine under EUA. Significant predictors of COVID-19 vaccine uptake intentions were education, having insurance, scoring high on subjective norms, a positive attitude toward the vaccine, as well as high perceived susceptibility to COVID-19, high perceived benefits of the vaccine, scoring low on barriers to the vaccine, and scoring high on self-efficacy. Predictors of willingness to take a COVID-19 vaccine under EUA were age, race/ethnicity, positive subjective norms, high perceived behavioral control, positive attitudes toward the vaccine, as well as high perceived susceptibility to COVID-19, high perceived benefits of the vaccine, low barriers to the vaccine, and scoring high on self-efficacy for getting the vaccine. Concerns about rushed vaccine development appear to reduce vaccine uptake intent, as well as willingness to get the vaccine under EUA. COVID-19 vaccine-related messages should both address concerns about the vaccine and its development and reinforce benefits of the vaccine (both factors significant in both models). Vaccine efforts may need to go beyond just communications campaigns correcting misinformation about a COVID-19 vaccine to also focus on re-establishing public trust in government agencies.