The tests, which are sent to recipients upon request at covidtests.gov, are running low, while the Biden administration wants to reserve adequate stock in case of a fall surge, the official said.
Unless there is additional funding from Congress, the free tests will no longer be offered starting Friday. The White House had unsuccessfully asked Congress for $22.5 billion in COVID-19 relief funding in March.
The federal government began mailing free home testing kits in January, distributing approximately 600 million through its website.