The CDC's "community level" recommendations, updated on Thursday, say residents of 10 Arizona counties should be wearing well-fitting masks indoors in public, regardless of vaccination status or individual risk, including in K-12 schools and other community settings.

The guidance is updated weekly and ranks counties as low, medium and high, or green, yellow and orange. The Arizona counties designated as “high,” where masks are recommended, are Maricopa, Pinal, Apache, Coconino, Gila, La Paz, Mohave, Navajo, Yavapai and Yuma. Greenlee and Santa Cruz are “medium,” and Pima, Graham and Cochise are “low.”

The metrics are based on a county’s COVID-19 hospital bed use, COVID-19 hospital admissions and case rates for the virus over the past week.

Slightly more than one-third of counties in the U.S., or 35%, were designated at the "high" level on Thursday, while about 40% were "medium" and 25% were "low."

Masks are not explicitly recommended when communities are in the low level, nor for most at the medium level except for certain people, including those who are immunocompromised, at high risk for severe disease, or have a household or social contact at high risk for severe disease.

The CDC also recommends "enhanced prevention measures in high-risk congregate settings" in communities designated at the medium level.

In addition to Arizona, other areas of the country with large swaths of "high" level counties include California, Florida, Oregon, Louisiana and Montana.

Reported cases of COVID-19 in Arizona continue at relatively high levels, and the percentage of positive tests in the state was the highest reported since January, according to the state's most recent weekly update, which was updated Wednesday.



Arizona, like other states, is seeing an ongoing case increase now largely driven by two contagious subvariants of the virus, BA.4 and BA.5, with BA.5 the more dominant of the two. It's also likely contributing to reinfections given its contagiousness and ability to evade antibodies. 

On July 1, the CDC placed nine counties in Arizona in the "high" category, which was the first time Maricopa, Coconino and Yavapai counties had been rated "high" since the CDC began posting the data in late February. 

On July 8, the CDC downgraded all but three Arizona counties from the high level. Maricopa County had been downgraded to "medium." Three counties have been rated "high" for three consecutive weeks: Navajo, Apache and Mohave counties.