The U.S. Centers for Disease Control and Prevention counts only deaths in which the presence of the coronavirus is confirmed in a laboratory test. “We know that it is an underestimation,” agency spokeswoman Kristen Nordlund said.

A widespread lack of access to testing in the early weeks of the U.S. outbreak means people with respiratory illnesses died without being counted, epidemiologists say. Even now, some people who die at home or in overburdened nursing homes are not being tested, according to funeral directors, medical examiners and nursing home representatives.

Postmortem testing by medical examiners varies widely across the country, and some officials say testing the dead is a misuse of scarce resources that could be used on the living. In addition, some people who have the virus test negative, experts say.