A new report from the National Center for Health Statistics says more than 3,500 people in the U.S. died from long COVID-19 the pandemic’s first 30 months compared to more than 1 million deaths from initial COVID-19 infection.

That number is likely low.

Death certificates in the National Vital Statistics System reveal people 75-84 years old saw the highest percentage of long COVID-19 deaths during Jan. 1, 2020–June 30, 2022, followed by adults 85 and older.

The death rate was highest among American Indian or Alaska Native people (14.8 per 100,000), even though more than three-quarters of deaths occurred among non-Hispanic White people.

Despite having higher mortality rates for COVID-19 itself, non-Hispanic Black and Hispanic people did not experience higher long COVID death rates. The authors suggest higher death rates during the disease’s acute phase might have left fewer survivors to develop long COVID-19. Poor access to health care and discrepancies in post-COVID diagnoses and reporting might also have played a role.

The proportion of all COVID-19 deaths involving long COVID reached its height in June 2021 (1.2%) and in April 2022 (3.8%). Both dates fell amid periods of waning COVID-19 deaths.

At the time of the study, the International Classification of Diseases lacked a long COVID code, so the authors limited their tallies to certificates bearing the code for COVID-19 (U07.1) and cause-of-death phrases synonymous with long COVID, such as “chronic COVID,” “long COVID,” “long haul COVID,” “long hauler COVID,” “post-acute sequelae of COVID-19,” “post-acute sequelae SARS-CoV-2 infection,” “PASC,” “post COVID,” and “post COVID syndrome.”

The World Health Organization has since approved the 10th revision of the International Classification of Diseases, which now includes mortality code U09.9 for long COVID-19.

In the meantime, a known potential for lags and misclassifications mean the count is likely conservative.