The Biden administration plans to mandate that private health insurance providers reimburse people for over-the-counter COVID-19 tests to make those at-home kits free.

The federal health, labor and treasury departments will issue the guidance to insurers by Jan. 15, according to senior administration officials on a press call late Wednesday.

More than 150 million people in the U.S. have private health insurance and will be able to get the cost of at-home tests reimbursed. It remains to be determined just how many tests and at what frequency will be covered by insurers under this new guidance.

For those who don’t have private insurance, the administration plans to distribute millions of free tests to community health sites, including rural clinics. There are currently more than 20,000 free testing sites across the country for anyone to access.

The reimbursement guidance is meant to bolster the fight against COVID-19 as the new omicron variant spreads. Omicron has been designated as a “variant of concern” by the World Health Organization.

The first case of the omicron variant in the U.S. was reported Wednesday in San Francisco. The variant, which was first detected by scientists in South Africa, has also been found in more than 20 other countries so far.

Researchers have yet to determine if the new variant is more contagious than previous variants of the virus, such as delta.

On Wednesday’s press call, Biden administration officials echoed President Joe Biden’s statement Monday that “while this new variant is a cause for concern, it is not a cause for panic,” adding that the country has “the tools we need to confront this variant.”

Even as there is still much that is unknown about omicron, vaccines continue to be the most effective barrier against severe cases of COVID-19 and the virus’s spread, providing vaccinated people with strong protection against hospitalization or death.

On Wednesday’s call, the Biden administration also announced new requirements for all international travelers coming into the U.S., starting next week, to test negative for COVID-19 within one day of departing for the U.S., versus the current requirement of testing negative within three days. The U.S. already requires that all foreign travelers to the U.S. be fully vaccinated.

In response to the omicron variant, the U.S. and other countries had announced restrictions on travel from countries in southern Africa.

Biden administration officials encouraged people who are fully vaccinated to get their booster shots, noting that more than 100 million people who are eligible haven’t gotten boosters yet.

“If you’re not vaccinated, get vaccinated,” Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said Sunday. “If you’re fully vaccinated, get boosted, and get the children vaccinated also.”