WASHINGTON (AP) — Under criticism after weeks of shortages, President Joe Biden's administration is working to make COVID-19 rapid test kits more available and accessible to Americans by boosting supply and lowering costs. A new federal website to request free test kits launches Wednesday, with the first shipments going out to Americans by the end of the month. In addition, most Americans will be able to get reimbursed for tests that they purchase starting Saturday.

Key details about the new programs:

HOW CAN I REQUEST A FREE TEST?

Starting Wednesday, Jan. 19, free tests can be ordered at covidtests.gov. The first tests will ship by the end of January. The White House says "tests will typically ship within 7-12 days of ordering" through the U.S. Postal Service. USPS reports shipping times of 1-3 days for its first-class package service in the continental United States. Shipments to Alaska, Hawaii, Army Post Office (APO), Fleet Post Office (FPO) and Diplomatic Post Office (DPO) addresses will be sent through Priority Mail.

Importantly, given the shipping and process times, Americans will need to request the tests well before they meet federal guidelines for requiring a test.

WHEN SHOULD I TEST?

The Centers for Disease Control and Prevention recommends at-home testing when people experience COVID-19 systems including fever, cough, sore throat, respiratory symptoms and muscle aches; five days after a potential COVID-19 exposure; or as part of test-to-stay protocols in schools and workplaces.

HOW MANY TESTS CAN I ORDER FROM THE WEBSITE?

The White House says that "to promote broad access," shipments from covidtests.gov will initially be limited to four rapid tests per residential address, no matter the number of occupants.

IS THERE ANOTHER WAY TO GET A TEST KIT FOR FREE?

Starting Saturday, private insurers will be required to cover the cost of up to eight at-home rapid tests per month per insured person, according to a new Biden administration rule.

People will have the option of buying tests at a store or online, then seeking reimbursement from their health insurance provider. Insurers are being incentivized to work with pharmacies and retailers to develop plans to cover the cost of the tests with no out-of-pocket cost to customers, but those programs will not be immediately widespread.

Those with public health insurance through Medicare, or without insurance, will be directed to covidtests.gov to order tests or to community health centers in their area offering free testing.

HOW WILL I BE REIMBURSED?

The Biden administration says the procedures will differ from insurer to insurer, and it is encouraging Americans to save receipts from rapid test purchases for later reimbursement and to reach out to their insurance providers for information.

Critically, the requirement only covers purchases on or after Saturday. Insurers are not expected to retroactively reimburse the cost of tests purchased earlier.

WHAT ARE OTHER TESTING OPTIONS?

The Biden administration is emphasizing that the website is just one tool for Americans to access COVID-19 testing. Millions of free tests are available at participating pharmacy locations, community health centers and Federal Emergency Management Agency-backed sites in some parts of the country experiencing a surge in cases.

WHICH HOME TEST WILL I GET?

That will vary. The federal government has secured more than 420 million tests for distribution through covidtests.gov already, with plans to increase the order to 1 billion tests in the coming weeks. All of the tests supplied will be authorized by the Food and Drug Administration and are capable of detecting the more-transmissible omicron variant of COVID-19, which is the dominant strain in the U.S. While they are packaged differently and may use slightly different procedures, officials said, the test mechanisms of detection and effectiveness are generally the same. All tests will come with detailed instructions.

WHY IS BIDEN BUYING THESE TEST KITS?

It represents an acknowledgement by the president that the administration needs to do more to increase access to COVID-19 testing, which is an important tool to help slow the spread of the coronavirus.

In cases where infected people show symptoms or not, testing is the only way to find out if they have the virus so they can avoid being out and about and potentially spreading disease.

Demand for test kits soared as the holidays neared and people grew eager to test themselves and their families before traveling and as the omicron variant spread rapidly in just a few weeks to become the dominant strain in the U.S.

Biden's promise of 1 billion test kits is in addition to the administration's earlier pledge to send 50 million rapid tests to community health centers across the country.

HOW MUCH WILL THE PROGRAM COST?

The White House estimates the cost of purchasing and distributing the first 500 million tests at about $4 billion. That will be paid for with money from the $1.9 trillion coronavirus relief bill Biden signed into law in March.

WILL THE GOVERNMENT PROGRAM MAKE IT HARDER FOR ME TO FIND A TEST AT THE DRUGSTORE?

White House officials say the covidtests.gov tests are coming from new manufacturing capacity and should not interfere with existing supplies that drugstores, health clinics and state governments are relying on.