Since President Joe Biden announced a plan to ship free COVID-19 tests in Jan. 2022, the US Post Office has delivered 737 million COVID tests to American homes. But that program could end soon, as the federal government has announced an end to the three-year-long public health emergency.

After May 11, many services provided by the federal government will now fall to American citizens or their health insurance companies, and the lack of budgeted funds could mean the end of free COVID-19 tests any time now.

In 2022, the US Postal Service delivered millions of free COVID-19 tests -- up to 16 tests per household -- but the program was halted in September last year due to lack of funding. At that time, the White House said that it would reserve a supply of COVID-19 tests for the winter season, and it's now shipping tests again.

"In the absence of Congress providing additional funding for the nation's COVID-19 response, the administration has acted with its limited existing funding to add more at-home COVID-19 tests to the nation's stockpile and support this round of ordering ahead of continued increases in COVID-19 cases," the White House said in a statement.

Below, find out how to request new COVID-19 tests, track your order and learn about other places to get free test kits.

For more on COVID-19, learn why the expiration date on your test kit might be wrong.

How does the free COVID-19 test program from USPS work?

In January 2022, President Joe Biden announced the launch of CovidTests.gov, a website that let households order four free rapid antigen COVID-19 tests shipped by USPS. The site added four more free tests in March, and then another eight more in May. The latest round of shipments also includes four COVID tests.

Unlike some complicated government applications, ordering free tests from the Postal Service is simple. It takes less than two minutes to complete a short form asking for your name and mailing address, and the tests ship in about a week or two. Americans without internet access or those who have trouble ordering online can request tests using a toll-free phone number -- 800-232-0233.

How do I order free COVID-19 tests from USPS?

You only need to provide the US Postal Service with a few bits of information to get your free test kits. You won't be asked to provide any credit or debit card details, as both the tests and the shipping are free. Here's how to get your free test kits. 

1. Visit special.USPS.com/testkits. You can also get there via covidtests.gov.

2. Enter your contact details and shipping information.

3. Click Check Out Now.

4. Verify that your information is correct and select Place My Order.

All orders will be shipped via First Class Package Service.

People who can't access the website or who have trouble ordering online can call 800-232-0233 to order their free tests.

When will my free COVID-19 test kits arrive? 

Tests are typically sent out within seven to 12 days of an order being successfully placed and are delivered by the USPS within one to three days of shipping.

How can I track my order of free COVID tests?

Once you place your order, you should receive a confirmation email. When your package ships, you'll receive email notifications providing you with shipping updates, including a tracking number and estimated delivery date. Note that for the third round, you'll receive two packages that'll likely arrive on different days, so look for two confirmation emails with your tracking numbers.

Once you receive it, you can either click the tracking link or copy and paste the tracking number into the Postal Service's website's tracker.

Is it OK to use COVID-19 tests that were left outside in the cold?

According to the Food and Drug Administration, manufacturers have ensured that the tests remain stable at various temperatures, "including shipping during the summer in very hot regions and in the winter in very cold regions."

But a test may be damaged by being left outdoors in freezing temperatures or being used immediately after being brought inside from freezing temperatures. 

The ideal temperature to store rapid antigen COVID-19 test kits is between 59 and 86 degrees Fahrenheit. 

How else can I get more free COVID-19 tests?

Along with the four free tests from the Postal Service, you have a few options for finding similar at-home tests for free. First and foremost, if you have private health insurance, you can get another eight free tests per person per month. That means a family of four gets 32 free tests monthly. 

In January, the Biden administration declared that health insurance companies would be required to cover at-home tests. Participants can either receive their eight free tests a month from provider-based pharmacies or be reimbursed by their provider for up to $12 for each test they purchase.

Major pharmacy chains originally required customers with insurance to pay for tests upfront and get reimbursed, but some have now shifted to a model where most customers with insurance cards can get eight tests per month at no cost. Both Walgreens and CVS allow customers with insurance cards to order COVID-19 tests for free on their websites.

At-home COVID-19 tests are also eligible expenses for flexible spending accounts and health savings accounts.

Medicare was not initially included in the plan to distribute free COVID-19 tests, but in April the Centers for Medicare & Medicaid Services announced that participants with Plan B or those enrolled in Medicare Advantage plans are also eligible to receive eight free tests a month.

If you're not insured or covered by Medicare, you still can get free COVID-19 tests. As part of the Biden administration's National COVID-19 Preparedness Plan, the Department of Health and Human Services has provided millions of free COVID-19 tests to community health centers and Medicare-certified rural health clinics.

You can search for a local health center or clinic with free COVID-19 tests near you using a tool on the HHS website.

For more on COVID-19 and at-home testing, learn about the COVID-19 testing guidelines from the FDA and how to spot fake COVID tests.