On May 13, 2020, the Wisconsin Supreme Court declared the state's Safer at Home Emergency Order (https://evers.wi.gov/Documents/COVID19/EMO28-SaferAtHome.pdf) "unlawful, invalid, and unenforceable,"* thereby increasing opportunities for social and business interactions. By mid-June, Winnebago County,† Wisconsin experienced an increase in the number of infections with SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), with the largest increase among persons aged 18-23 years (young adults) (1). This age group§ accounts for 12.5% of the population in the county. To identify factors that influence exposure to COVID-19 among young adults in Winnebago County, characteristics of COVID-19 cases and drivers of behaviors in this age group were examined. During March 1-July 18, 2020, 240 young adults received positive SARS-CoV-2 test results, accounting for 32% of all Winnebago County cases. In 30 key informant interviews, most interviewees reported exposure to misinformation, conflicting messages, or opposing views about the need for and effectiveness of masks. Thirteen young adults described social or peer pressure to not wear a mask and perceived severity of disease outcome for themselves as low but high for loved ones at risk. Having low perceived severity of disease outcome might partly explain why, when not in physical contact with loved ones at risk, young adults might attend social gatherings or not wear a mask (2). Exposure to misinformation and unclear messages has been identified as a driver of behavior during an outbreak (3,4), underscoring the importance of providing clear and consistent messages about the need for and effectiveness of masks. In addition, framing communication messages that amplify young adults' responsibility to protect others and target perceived social or peer pressure to not adhere to public health guidance might persuade young adults to adhere to public health guidelines that prevent the spread of COVID-19.