Underascertainment of SARS-CoV-2 infections is a common problem during the COVID-19 pandemic. Estimating the degree of underascertainment can be challenging, but it is useful for guiding public health responses. Here we estimate underascertainment across time for Uruguay during 2020, adapting a method developed by Russell et al. (2020) to incorporate age-stratified case reports, as well as for using hospitalization and ICU admission data. Video