Life expectancy at birth in the U.S. declined nearly a year from 2020 to 2021, according to new provisional data from the CDC.

Why it matters: It's the latest evidence of the toll the COVID pandemic took on Americans' health and takes the U.S. life expectancy at birth to its lowest level — 76.1 years — since 1996.

• Together with recent data showing life expectancy fell 1.8 years between 2019 and 2020, that means life expectancy at birth fell by 2.7 years over two years — the largest two-year decline since 1921–1923.

Be smart: COVID-19 was the biggest driver, followed by unintentional injuries and heart disease.

• The losses were offset in part by decreases in deaths attributed to the flu and pneumonia, which is likely tied to COVID mitigation measures such as masking and social distancing.