There has been an increase in reported cases of myocarditis and pericarditis following COVID-19 mRNA vaccines (Pfizer-BioNTech and Moderna), particularly in adolescents and young adults since April 202, case rates per million doses after second doses of the vaccine are higher than expected for this age group. The pathophysiology of myocarditis after COVID-19 vaccination is undetermined at this time. However, there have been multiple reports of myopericarditis associated with active COVID-19 infection, both as a late complication in adult survivors of COVID-19 and as part of multi-inflammatory syndrome in children (MIS-C). The pathogenesis of myocarditis or pericarditis associated with COVID-19 infection is thought to be a combination of direct viral injury or host immune response leading to myocardial damage.