As the coronavirus disease 2019 (COVID-19) crisis enters its next phase, attention turns to the widespread testing programs needed to resume and maintain normal life activities. Effective prevention and surveillance require testing for active infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and for antibodies that indicate prior infection and potential immunity. There is an established approach for infected individuals: mild cases self-isolate; and severe cases receive treatment. But what is the appropriate response for people with positive antibody tests?