What does new mask guidance from the Centers for Disease Control and Prevention mean? For Massachusetts residents, it depends on where you are exactly.

If you are indoors in public in Boston, the CDC would suggest putting on a mask, even if you are vaccinated. But it’s not necessary if you cross the river into Cambridge or cross the street into Brookline, according to the CDC’s new recommendations released Tuesday.

Some local health officials say this geographic variation is confusing and are calling for more consistent recommendations that cover the entire state, region or country.

“We should all be on the same page,” said Swannie Jett, the Health Commissioner in Brookline.

The CDC’s new mask recommendations are a reversal from its previous stance, which said vaccinated people could mostly go without masks. The federal agency is now recommending that, even if you are vaccinated, you should don a face covering when indoors in public in virus hot spots. The CDC is defining hot spots at the county level based on new cases and positive test rates.

“Now we’re just going back and forth. What that does is confuse people,” Jett said. “We are waiting for the governor's office to determine how to interpret the new recommendation by the CDC.”

On Wednesday at a press conference, Massachusetts Gov. Charlie Baker said he is considering the new CDC guidance and will have more to say soon.

In the Commonwealth, only Barnstable County is currently categorized as an area of high transmission, while four counties — Bristol, Dukes, Nantucket and Suffolk — are designated as areas of substantial transmission. In all five counties, the CDC recommendation is that everyone wear masks indoors in public. Nearly two-thirds of the country has cases loads or test rates such that the CDC recommends everyone mask, officials said.

Technically Somerville is not one of the places the CDC recommends everyone mask up, yet the city is still encouraging people wear masks indoors in public. Doug Kress, the Director of Health and Human Services in Somerville, said it’s easier that way since Somerville (in Middlesex County) is bordering Boston (in Suffolk County) where there is the CDC mask recommendation.

“We know where the lines are, but most community members do not. So, that's why we encourage everybody — whenever you’re in Somerville or whenever you’re inside — to wear masks,” Kress said.

Kress agreed with Jett that a uniform policy would offer clarity.

“It’s much easier if we have some consistency across all of our area,” Kress said. “Because everybody knows the rules then, and you don’t have to question them.”

Kress emphasized that both the CDC and the Somerville guidance is simply a recommendation and not a mandate. However, he said, he always wears a mask while out because “I think people look to others and try and follow what other people are doing.”