Your COVID test may still be good, even if the date printed on the box has passed. The FDA extended the shelf life of many at-home tests multiple times during the pandemic, so the expiration date on the packaging is often outdated. The only reliable way to check is to look up your test’s lot number on the FDA’s website.
How to Check Your Test’s Real Expiration Date
Every at-home COVID test has a lot number printed on the outer packaging, usually near the original expiration date. You need this number to look up whether your test received a shelf-life extension. The FDA maintains a page listing authorized at-home tests with links to each manufacturer’s updated expiration information. You can find it by searching for “FDA at-home OTC COVID-19 diagnostic tests” or going directly to the FDA’s expiration dating page.
Once you find your test brand, look for your specific lot number in the manufacturer’s table. If your lot number appears with a new expiration date, that extended date is the one to trust, even if it doesn’t match what’s printed on your box. If your lot number isn’t listed, the expiration date was never extended, and you should throw the test away. The North Carolina Department of Health and Human Services also maintains a helpful page that links directly to the FDA information for popular brands.
One important note: the FDA is no longer extending expiration dates for newly manufactured test kits. Extensions only apply to older tests that were produced during the pandemic’s peak. If you bought a test recently, the printed expiration date is the correct one.
Why Expired Tests Give Wrong Results
At-home COVID tests work by using antibodies that react to a specific protein on the virus. Over time, those antibodies degrade. They lose their ability to detect the viral protein reliably, which means an expired test is more likely to tell you you’re negative when you’re actually infected. This is called a false negative, and it’s the main risk of using an expired test.
A positive result on an expired test is still meaningful. If the degraded antibodies managed to detect the virus despite being weakened, you almost certainly have COVID. But a negative result on an expired test tells you very little. You could easily be sick and contagious without the test picking it up.
Storage Conditions Matter Too
Even a test that hasn’t technically expired can be unreliable if it was stored incorrectly. Most COVID tests need to be kept below 86 degrees Fahrenheit. Heat damages the chemicals that identify viral proteins, and this damage is irreversible. If your test sat in a hot car, a mailbox during summer, or a garage that regularly exceeds that temperature, the reagents inside may have broken down regardless of the expiration date.
This isn’t a matter of degree. As one UCLA Health expert put it, these tests aren’t meant to be outside their temperature window at all. If you live somewhere with hot summers and your tests were stored in an uncontrolled environment, treat them as unreliable even if the dates check out.
What to Do If Your Test Is Expired
If your test is truly past its extended expiration date or you can’t verify the lot number, replace it. At-home COVID test kits are available at local pharmacies, and your health insurance may cover them. You can also check your state health department’s website for information on free testing options in your area, since some communities still offer no-cost testing through local programs or clinics.
If you’re symptomatic and only have an expired test on hand, using it is better than nothing, but only if the result is positive. A positive result is trustworthy. A negative result should not reassure you. Follow up with a new test or an in-person test at a pharmacy or medical facility if you have symptoms and your expired test reads negative.