The overarching goal of the RADx-UP initiative is to understand the factors associated with disparities in COVID-19 morbidity and mortality and to lay the foundation to reduce disparities for those underserved and vulnerable populations who are disproportionately affected by, have the highest infection rates of, and/or are most at risk for complications or poor outcomes from the COVID-19 pandemic. The Testing Core for RadX-UP reviews protocols and ensures that diagnostic testing is conducted and reported in a rigorous and appropriate manner.