At-Home COVID Tests Are Still Effective in 2023 — and You Can Still Get Them for Free

Update, June 20: As of June 1, you can no longer order free COVID-19 tests from the federal government and USPS. A message on the covidtests.gov site says that ordering has “been suspended to preserve remaining supply.” 

As a new COVID-19 variant rapidly emerges, many are wondering how tools such as at-home testing will fare against the latest virus evolutions.

The good news is that testing, along with vaccines and post-infection treatments, are still readily available, and infectious disease experts say these remain some of our best defenses against the spread of COVID-19.

Do at-home antigen tests work with the latest COVID-19 variant?

Yes! There is little evidence showing that at-home COVID-19 antigen tests work any differently with the newer strains of the virus, including XBB.1.16, also known as arcturus.

“The FDA data suggests the antigen tests currently in use are as effective in detecting arcturus as they are with other subvariants of omicron,” said Dr. John Swartzberg, clinical professor emeritus of the Infectious Diseases and Vaccinology division at UC Berkeley.

In general, rapid antigen tests are less sensitive and therefore less likely to detect an infection compared with polymerase chain reaction (PCR) tests. PCR tests look for viral genetic material, according to the Centers for Disease Control and Prevention, whereas antigen tests detect proteins on the surface of the virus.

When (and how) should I use an antigen rapid test to get the most accurate result?

If you were exposed to someone with COVID-19, but are not experiencing symptoms, or your symptoms are mild, one rule of thumb is to test five days after the exposure, according to Dr. Peter Chin-Hong, an infectious disease expert and professor at UCSF.

If you’re looking to test before a large event or before visiting someone who may be particularly vulnerable to COVID-19, test right before the visit to get the most accurate read.

“Test just before the visit if you’re going to check before seeing Grandma,” Chin-Hong said.

And, if you have COVID symptoms and test negative, “take precautions as if you have COVID and repeat the test every one to two days,” Swartzberg said.

What about false positives or negatives?

Overall, hospitalizations and deaths stemming from COVID-19 are near their lowest since the start of the pandemic. During lulls like this, there is a higher likelihood that an antigen test could yield a false positive.

“The lower it is in the community, the higher the chance you might get a false positive. If you get a positive out of the blue, try to track down a PCR,” said Chin-Hong.

However, false positives are still quite rare. “If the antigen test is positive, it is very likely you have COVID,” said Swartzberg. “If it is negative, you cannot feel confident you do not have COVID,” he added, saying that many tests will show up negative in the early stages of infection.

Improving your sample collection for at-home tests will also improve your chances of getting an accurate result. For example, when swabbing the nostril, scrape the inner lining of the nose rather than just the snot and boogers hanging about. That’s why antigen tests generally recommend you blow your nose before swabbing.

“Make sure you’re not just swabbing snot but you’re swabbing the cells in your nose. You have to swab relatively hard,” Chin-Hong said.

Some but not all doctors recommend swabbing the inside of the throat also, especially if a sore throat is presenting as a symptom.

Also important when buying at-home tests is to make sure the tests have not expired (more on that below) and that they are not counterfeit. Most major pharmacies carry only FDA-approved antigen tests. If you’re not sure, check for a few indicators like misspellings or lack of an expiration date.

A full list of FDA-approved tests can be found here.

Can I still get free antigen tests anywhere?

There’s no getting around this fact: In 2023, finding free or low-cost antigen COVID tests is much harder than in previous years of the pandemic. And certainly, the days when packs of antigen COVID tests were given out for free are gone.

Here’s how to keep getting free or low-cost antigen tests:

Order your (last) four free tests from the White House via USPS

The White House website covid.gov/tests has been offering separate orders of free COVID antigen tests for each household during the pandemic. This program looks to be continuing after the federal public health emergency ended on May 11, but it’s unclear how much longer it’ll last. So if your household hasn’t ordered any free tests since Dec. 15, 2022, consider placing your order for another four free COVID tests ASAP — in case the program ends abruptly.

If you have health insurance, get eight antigen tests reimbursed per month

In other states, the recent end of the federal public health emergency for COVID means insurers no longer have to keep covering the costs of up to eight over-the-counter antigen tests a month.

But California has enacted laws that force insurers to keep reimbursing their members for the costs of eight tests each month (as well as Paxlovid). This also applies to people on Medi-Cal, but this is only in effect until Nov. 11. Read about how to get reimbursed for COVID tests by your insurer.

If you’re on Medicare Part B (medical insurance), you can keep getting eight free over-the-counter COVID tests after May 11. However, people on Medicare Part A (hospital insurance) have lost access to those free tests.

For free testing, consider getting a PCR test instead

PCR testing is more accurate than an antigen test — because it’s more sensitive at picking up traces of the coronavirus in your body — but it may take longer to get your results than with an at-home test, which could affect your ability to source a prescription for Paxlovid quickly (see below).

Currently, there are still some sites offering free COVID testing around the state; go to myturn.ca.gov/testing and apply the “Free Sites” filter from the drop-down menu. It’s not yet clear how many of these sites will continue operating in the coming months after the end of the federal public health emergency. If you have health insurance, you may be able to get a PCR test ordered by your health care provider with the costs covered.

For more ideas on how to find a free or low-cost COVID test near you, see the KQED guide.

Another key use for antigen tests: Getting Paxlovid in time

As of Feb. 2023, you no longer need proof of a positive COVID test to get a prescription for Paxlovid, the powerful antiviral COVID treatment.

But for it to be effective, health officials recommend starting a course of Paxlovid within five days of a positive test. This means it is still very important to take a test as soon as you suspect you have COVID — and a big part of that is having swift access to a test. Now that there’s no shortage of Paxlovid, the drug is no longer reserved for people most at risk of severe illness from COVID, and everyone is encouraged to contact a health care provider to see whether they qualify.

Since results from PCR tests can take longer, and some testing sites may not be available at certain times you need the test — like evenings and weekends — consider using the methods listed above to make sure you have access to at least one antigen test available at home if you begin to feel the symptoms of COVID.

How to check whether your antigen tests have expired — or had their shelf life extended

You may be lucky enough to have an existing supply of antigen tests from a while back — but it’s important to check that using those tests will still give you an accurate COVID test result.

Check the expiration date on the box, but don’t panic if it’s passed. Before you toss the box, check the FDA’s list of antigen test types to see whether the one you’re holding has had its shelf life extended by the manufacturer. The FDA says that if a test’s shelf life has been extended, it’s because the manufacturer has given the agency enough “data showing that the shelf-life is longer than was known when the test was first authorized.” In other words, it’s still OK to use that test.