Expiration dates for COVID tests from government may be months later than anticipated

Consumers who've ordered free home coronavirus tests through a federal website could be in for a surprise: they might get kits with expiration dates that passed months ago.

But experts say you shouldn't immediately discard those tests. Even though you might not see it on the packaging, the federal government has extended expiration dates on many of these home tests. Consumers can check this Food and Drug Administration website to find extended expiration dates for home coronavirus tests.

How can I order free home COVID tests from the federal government?

Consumers can now order four free coronavirus home tests per household through the government-run website CovidTests.gov.

The U.S. Department of Health and Human Services has tests on hand that will be shipped to homes by the United States Postal Service beginning the week of Oct. 2. HHS also said it will award $600 million to a dozen domestic coronavirus test manufacturers to shore up the government's supply of home tests. The investment will deliver about 200 million new over-the-counter coronavirus tests over the next 18 months, officials said.

How can I tell if my test has expired?

The coronavirus home test kits have an expiration date printed on the box. Yet the test kits will include multiple reminders for consumers to check the FDA website for extended expiration dates. The test kits will be delivered with a sticker on the box and a leaflet in the box informing consumers to check the FDA for extended expiration dates. Consumers also can call the agency's hotline at 1-888-INFO-FDA for more information.

How long have COVID test expiration dates been extended?

The FDA extends expiration dates when the manufacturer has data showing the test can deliver accurate results beyond the original expiration date.

The length of the extension varies by test maker for 37 approved home coronavirus tests, which are mostly "antigen" tests to detect a viral protein on the surface of the coronavirus. The shortest shelf life is four months for the 3EO Health COVID-19 Test. Tests from these six companies have the longest shelf life of 24 months: ACON Laboratories, Azure Biotech, Celltrion USA, GenBody, Princeton BioMeditech and Siemens Healthineers.

The shelf life for the popular Abbott BinaxNOW COVID-19 Antigen Self Test has been extended to 22 months. You can view the lot number of your Abbott BinaxNow test to find the updated expiration date.

My COVID test is beyond the extended expiration date. Can I still use it?

The FDA advises people to not use a coronavirus test beyond the extended expiration date. The test parts may degrade or break down, so kits used beyond the extended expiration date could give inaccurate test results, the agency said.

My home test was left outside in hot or freezing temperatures. Can I still use it?

Test makers must perform stability testing to show the tests will work after being shipped in summer or winter. Still, extreme temperatures can affect test performance, the FDA said.

If you get a test kit that was delivered during hot or cold weather, you should bring the package inside to room temperature and not open it for a minimum of two hours. From there, consult the test's instructions. For example, if the control lines don't appear in the right locations, the test might not deliver accurate results.

What can the antigen COVID tests detect?

Most home tests are antigen tests that typically deliver results in about 15 minutes. Antigen tests are less sensitive than molecular PCR tests and less likely to detect the virus early in the infection, but experts say the tests can detect the virus when a person is infectious and likely to pass it to others.

For antigen tests, the FDA recommends consumers repeat testing following a negative result to reduce the risk an infection may have been missed. Those with symptoms should test again 48 hours after a negative test. If you don't have symptoms, the FDA recommends taking up to three tests over four-plus days with negative results, with 48 hours lapsing between each test.

Contributing: David Robinson, USA TODAY Network New York State Team

This article originally appeared on USA TODAY: Free government COVID tests may work after expiration date, FDA says