The federal government’s giveaway of at-home COVID-19 tests will end on September 2, unless Congress comes through with surprise funding before then, the Biden administration has announced.

Money for the program has run out, administration officials say. They blame Congress, which failed to act when the White House this spring asked for another $2.25 billion in funding for COVID relief efforts.

Officials plan to hold on to the remaining stock of tests in case of a new surge this fall, a senior Biden administration official told NBC News on August 28.

Those who have not taken advantage of the third round of free tests are eligible to place an order before September 2, however. They will receive eight at-home tests.

Federal officials have been issuing free COVID tests since January, distributing an estimated 600 million so far. It’s unclear how many the government still has on hand.

Testing for COVID-19 has been on the decline worldwide for months. That’s due in part to the availability of home tests, the results of which are rarely reported to public health officials. In July, wastewater indicators showed that COVID infections were actually near all-time highs in some parts of the U.S.

While free home test distributions are being paused, most people in the U.S. will still have a free testing option via private insurance, or Medicare or Medicaid, at health care facilities.