Today, one day before the presidential inauguration, the United States registered its 400,000th death to COVID-19.

As confirmation, since March 2020, at least 400,000 more Americans have died than would have in a normal year, a sign of the broad devastation wrought by the coronavirus pandemic.

An analysis of mortality data from the Centers for Disease Control and Prevention shows how the pandemic is bringing with it unusual patterns of death, even higher than the official totals of deaths that have been directly linked to the virus.

Deaths nationwide were 18 percent higher than normal from March 15, 2020, to Dec. 26, 2020. These numbers may be an undercount since recent death statistics are still being updated.

This analysis examines deaths from all causes — not just confirmed cases of coronavirus — beginning when the virus took hold in the United States last spring. That allows comparisons that do not depend on the accuracy of cause-of-death reporting, and includes deaths related to disruptions caused by the pandemic as well as the virus itself. Epidemiologists refer to fatalities in the gap between the observed and normal numbers of deaths as “excess deaths.”