Kaiser Permanente Martinez Medical Offices is one of the many locations hosting COVID-19 testing and vaccination sites around Contra Costa County, located at 200 Muir Road in Martinez, Calif. on January 13, 2021. (Samantha Laurey/Bay City News)

All but one of the greater Bay Area’s 11 counties are now in the state’s orange COVID-19 reopening tier as four more counties were assigned to the tier Tuesday.

Contra Costa, Monterey, Napa and Sonoma counties all moved into the orange tier for the first time since the pandemic’s lull in cases last fall, enabling them to expand indoor capacities for already opened businesses and reopen bars outdoors.

“California is making great progress in administering COVID-19 vaccine doses,” state Health and Human Services Secretary Dr. Mark Ghaly said. “We must continue to do our best to vaccinate Californians as safely and quickly as possible.”

The tier change from red to orange will allow the four counties to increase indoor capacity from 25 percent to 50 percent for sectors like places of worship, movie theaters and restaurants, while gyms and fitness centers will be allowed to raise capacity from 10 percent to 25 percent.

In addition, business sectors such as family entertainment centers, cardrooms, offices and wineries will be allowed to resume indoor operations after being limited to opening outdoors or being closed altogether in the more restrictive red and purple tiers.

Being in the orange tier will also enable bars to reopen outdoors with modifications like distancing between patrons and required masking when not eating or drinking.

A move to the yellow tier would allow the counties to resume indoor operations at bars at 25 percent capacity or 100 people, whichever is fewer, according to the California Department of Public Health.

Contra Costa County officials cautioned that the pandemic has yet to fully recede, and residents should continue taking precautions like masking, but acknowledged that the county’s move into the orange tier for the first time in five months represents hard-fought progress.

“We are still in a pandemic and people should continue to act accordingly: Keep wearing masks in public and get vaccinated as soon as you can,” Contra Costa County Health Officer Dr. Chris Farnitano said. “I still strongly recommend people to avoid most indoor activities with people outside of their own household until they are fully vaccinated.”

Sonoma County Health Officer Dr. Sundari Mase also advised residents to continue following the public health guidance that has helped the county quell its positivity rate down to 1.6 percent.

“We should all feel good about our progress against COVID-19,” Mase said. “We also want to move safely through the orange tier and not lose ground. Even as more of us are getting vaccinated each day, it is crucial to be aware of the surges happening in other parts of the country and avoid outbreaks here.”

Residents in all 11 Bay Area counties are encouraged to get vaccinated against the virus when they become eligible. Some counties, like Contra Costa, have already made the vaccine available to all residents age 16 and up.

Vaccination appointments can be made through local health departments as well as through the state’s My Turn vaccination appointment scheduling tool at https://myturn.ca.gov or by calling (833) 422-4255.

Solano County remains the only county in the region in the red tier. Orange tier restrictions will go into effect Wednesday for the four counties that changed tiers Tuesday.

Just two of the state’s 58 counties, Inyo and Merced, remain in the most restrictive purple tier.