evidence: The Table also presents leading causes of death in the US for the years 2015 to 2020.4 According to provisional data, in 2020, there were notable changes in the number and ranking of deaths compared with 2019.5 COVID-19 was the third leading cause of death in 2020, with an estimated 345 323 deaths, and was largely responsible for the substantial increase in total deaths from 2019 to 2020. Substantial increases from 2019 to 2020 also occurred for several other leading causes. Heart disease deaths increased by 4.8%, the largest increase in heart disease deaths since 2012. Increases in deaths also occurred for unintentional injury (11.1%), Alzheimer disease (9.8%), and diabetes (15.4%). Influenza and pneumonia deaths in 2020 increased by 7.5%, although the number of deaths was lower in 2020 than in 2017 and 2018. From 2019 to 2020, deaths due to chronic lower respiratory disease declined by 3.4% and suicide deaths declined by 5.6%.