(Bloomberg) -- The Biden administration has released another round of free at-home Covid-19 tests available through mail order.

Each US household is eligible for eight free tests at Covid.Gov/Tests, which will ship through the US Postal Service in two separate shipments. This is the third round of free tests since the program first launched in January. A second round became available in March. It comes as the US crosses the grim milestone of one million deaths since the pandemic began.

The widespread use of at-home tests has complicated public health officials' ability to track the pandemic because people don't always report positive results.

The more infectious variant BA.2 has meant greater spread, even among those vaccinated, boosted and with prior infections. Cases are once again surging across major metro areas like San Francisco which maintained low positivity rates over the past two years, and now has the highest in California. 

The White House has requested an additional $22.5 billion in funding from Congress for testing, vaccines and treatments.

Read More: Is It Covid or Flu? New At-Home Test Spots Multiple Viruses

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