Using data from the Centers for Disease Control (CDC) and BigQuery ML, Fivetran estimates that between March 1 and April 4, only 19% of symptomatic COVID-19 patients who visited their doctor were able to get tested. This percentage increased from nearly zero at the beginning of March to 60% at the end. By analyzing data on flu-like illnesses, Fivetran estimates that over 12 million Americans were infected with COVID-19 during this period. The model relies on several assumptions and is subject to uncertainty, but randomized serological surveys are now being conducted to validate these estimates.