Citing data from local state health authorities, the Covid Tracking Project reported 83,010 new cases on Friday.
US Surgeon General Jerome Adams has warned that hospital admission numbers are growing, but mortality rates are falling due to better patient care.
It comes as pharma giants AstraZeneca and Johnson & Johnson resume US vaccine trials after approval from regulators.
The World Health Organization (WHO) has also warned that countries in the Northern Hemisphere are at a "critical juncture".
"The next few months are going to be very tough and some countries are on a dangerous track," said director general Tedros Adhanom Ghebreyesus, speaking with reporters.
What are the latest US figures?
According to the Covid Tracking Project, nearly 8.5 million cases of coronavirus have been reported in America since the pandemic began.
The daily increase on Friday surpassed by more than 6,000 cases the tracking project's previous record of 76,842 on 17 July.
Over the last week, the US has tallied 441,541 new infections - its largest seven-day increase since the end of July.
The number of people who've died after contracting coronavirus has also steadily increased during the last six days, but is still significantly below the peak of over 2,000 daily deaths reported in April.