The Biden administration has relaunched its free COVID-19 testing program, allowing U.S. households to order at-home rapid antigen tests at no cost.

The taxpayer-funded program that paused in March resumed on Sept. 26, according to Dawn O'Connell, assistant secretary for preparedness and response at the U.S. Department of Health and Human Services (HHS).

“I am pleased to announce that we reopened the free COVID-19 test program today,” O’Connell said in a statement on X. She added that over 900 million tests have been distributed over the course of the lifetime of the program, which was first launched in early 2022.

A note on a website operated by HHS indicates that every U.S. household is eligible to order four free at-home tests, which can detect currently circulating COVID-19 variants. The website directs interested parties to a U.S. Postal Service (USPS) order form that can now be filled out, with the postal agency promising to start shipping the tests the week of Sept. 30.

HHS officials first announced plans to reopen the mail-based testing service in August, though at the time it was unclear when the COVIDtests.gov website would be reactivated.

A note on the USPS landing page featuring the order form states that some of the tests it will ship may show “expired” dates on the box, explaining that the U.S. Food and Drug Administration (FDA) has extended those dates.

“An extended expiration date means the manufacturer provided data showing that the shelf-life is longer than was known when the test was first authorized,” the FDA says in a note on a website about COVID-19 test expiry date extension. The website features a way to check if the expiration date on a given at-home COVID-19 test has been extended.

This is the seventh time that the federal government has relaunched the program, with last year’s revival of the service announced in a press release which also indicated that the Biden administration allocated $600 million to COVID-19 test manufacturing, aiming to stock up around 200 million over-the-counter tests for future use.

The relaunch of the testing program comes as public health officials brace for a possible uptick in COVID-19 cases during the fall and winter months, when respiratory viruses tend to spread more easily as people gather indoors.

The Centers for Disease Control and Prevention (CDC) has urged Americans to remain vigilant as new variants of the virus continue to circulate, though recent COVID-19 surges have not led to the same levels of hospitalizations and deaths seen in previous waves.

CDC data suggests that COVID-19 has become endemic, with the virus now behaving in a more predictable, seasonal pattern. This means it may have a significantly reduced impact on mortality, potentially comparable to that of seasonal influenza.