The COVID-19 pandemic left an unprecedented impact on the general public health, resulting in hundreds of thousands of deaths in the U.S. alone. Nationwide testing plans were initiated with drive-through being the currently dominant testing approach, which, however, exhausts personal protective equipment supplies, and is unfriendly to individuals not owning a vehicle. Walkup positive pressure testing booths are a safe alternative, whereby a health care provider situated on the inside of an enclosed and positively pressurized booth swabs a patient on the outside through chemical resistant gloves. The booths, however, are too prohibitively priced on the market to allow for nationwide deployment. To mitigate this, we present in this paper a safe, accessible, mobile, and affordable design of positive-pressure COVID-19 testing booths. The booths have successfully passed the Centers for Disease Control and Prevention and Health care Infection Control Practices Advisory Committee pressure, air exchange, and air quality requirements for positive-pressure rooms, following the guidelines for environmental infection control in health care facilities. The booths are manufactured using primarily off-the-shelf components from U.S. vendors with minimized customization, and the final bill of materials does not surpass USD 3,900. Since August 2019, five booths were deployed and used at the Johns Hopkins University School of Nursing, Baltimore City Health Department, and two community health centers in Baltimore. No health care provider was infected when using our booths, which have shown to facilitate walkup testing with decreased personal protective equipment consumption, reduced risk of infection, and enhanced accessibility to lower-income communities and nondrivers.