Author summary Why was this study done? It is known that people may suffer medical complications long after COVID-19, which are called post-acute sequelae (PAS). Similar sequelae are also known to happen after people are infected with influenza or other respiratory viruses. It is unclear whether PAS are a unique or more prominent feature of COVID-19 in comparison to influenza. What did the researchers find? Risk of PAS was only modestly higher (4%) after COVID-19 in comparison to influenza. By 91−180 days after infection, risk of PAS was similar for COVID-19 and influenza cases. Differences in PAS risk were driven by the fact that people with severe COVID-19 tended to have greater risk of severe PAS afterwards. What do these findings mean? PAS risk is similar among most COVID-19 and influenza cases, although people hospitalized for COVID-19 may be at particular risk. While PAS is well understood to occur after COVID-19, the burden of PAS associated with influenza may have been historically overlooked. As a key limitation of the study, outcomes encompass only PAS necessitating healthcare utilization. Patient-reported symptoms and quality-of-life measures are also important outcomes when measuring PAS.