Credit…Desiree Rios for The New York Times

Americans began receiving free coronavirus tests from the US government in the mail after they began accepting orders on Tuesday.

The Biden administration has said it will send 500 million rapid tests to Americans this month through the US Postal Service after the Omicron variant strained access to in-person and home testing. Each household is entitled to four free rapid tests and can order them at covidtests.gov.

Marcie Taylor, a marketing consultant in Santa Ana, Calif., said she received her tests on Friday after ordering them on Tuesday on the recommendation of her friend who sent her a link to the website. She said the package, which included two boxes containing two tests each, arrived earlier than expected by the tracking website.

Ms Taylor said her husband and two children, a 16-year-old and a 20-year-old, would try to make the tests last as long as possible because it was only one test per person.

“If you can order the kit, order it,” Ms Taylor said in an interview. “It gives you peace of mind to have it because there is a shortage in pharmacies.”

Ms Taylor was one of many people who posted on social media after receiving the tests at the end of the week.

“It bodes well for how things will go,” said Steve Hutkins, editor of the Save the Post Office blog.

Mr Hutkins said the Postal Service’s mission to deliver 500 million tests in a short period of time was a large, “but totally achievable” task.

To make these deliveries, the Post Office had to transform its operation.

Although postal workers typically process packages ready to ship, to manage the coronavirus testing operation, workers package and label test kits for delivery, according to a memo between the Postal Service and the American Postal. Workers Union.

The government has also updated 43 existing distribution centers across the country to prepare for testing, the memo said.

David Partenheimer, a spokesperson for the Postal Service, said in an email that to send out the tests, the agency was also using strategies that had helped it deliver 13.2 billion mail items and packages during the 2021 holiday season.

“These strategies, including additional staffing, investment in new processing equipment and operational efficiencies, and an expanded facility footprint, mean test kits can get to the Americans who want them quickly and efficiently,” Mr. Partenheimer said.

However, the operation was not transparent.

Some people who live in apartment buildings said they were unable to place an order on the website when it went live on Tuesday.

Jeffrey D. Zients, the White House’s Covid-19 response coordinator, said in a Friday press briefing that this issue affects “a very, very small percentage of people who live in apartment buildings.” that are not registered as multi-unit buildings within the Postal Service Database. To resolve this issue, the Postal Service advised people to file a service request online or contact the agency’s help desk at 1-800-ASK-USPS (1-800-275-8777).

Mr Zients declined to say how many people had placed orders for the tests, but said the White House would provide that data in the coming days. Nearly 70 million people visited the test website, according to government digital analytics.

The Biden administration has said a second batch of 500 million tests will be available in the spring.