Illinois has issued new guidance that will allow fully vaccinated people to go unmasked indoors, but businesses will not be required to verify people’s vaccination status.

That’s according to a release from Illinois Gov. JB Pritzker and information from a spokesperson at the governor’s office. The governor said the state is changing its current mask guidance, which requires masking indoors in most cases, to mirror new Centers for Disease Control and Prevention guidance that says fully vaccinated people do not need to wear a face covering inside.

Businesses can choose how to verify whether someone has been vaccinated — including by using the honors system.

“They are not required to verify vaccine status,” a spokesperson from the governor’s office said.

That’s a huge concern to an advocacy group of doctors and experts that formed out of the pandemic and has weighed in on numerous COVID-19 policies throughout the past year.

“Our concern is not that vaccinated people shouldn’t have to wear masks,” said Dr. Shikha Jain, co-founder of IMPACT. “The challenge is ensuring that people who aren’t wearing masks are indeed vaccinated and then protecting vulnerable people.”

The group was pushing the governor to continue the state’s current universal mask requirement, highlighting the fact that only 38% of the state is fully vaccinated.

Under the new guidance, businesses can decide to adopt stricter rules and continue to require masks indoors, regardless of vaccination status, an IDPH spokesperson said.

Illinoisans, regardless of vaccination status, are still required to wear masks on public transit, in congregate facilities and healthcare settings.

Some businesses say they’re keeping their mask mandate for now.

“You can’t tell on site who’s been vaccinated and who hasn’t,” said Julia Steiner, an employee at The Book Cellar in Chicago’s Lincoln Square neighborhood. “ And you know, we are working full time to sell books, not to stand at the door and check people’s vaccination cards.”

Jain, with IMPACT, said requiring proof of vaccination status would be one way to ensure that unmasked patrons are actually vaccinated, but the state has not answered questions if that’s one avenue business owners could take, or whether businesses could refuse to serve unvaccinated, unmasked patrons.

Large chains like Trader Joe’s, Target and Walmart have already come out to say they will no longer require masking for fully vaccinated patrons.

The city of Chicago has said it will fall in line with the state’s mask guidance, but has not yet issued a statement on the new rules.

This story has been updated to correct the name of the business, The Book Cellar.

Mariah Woelfel covers city government at WBEZ. You can follow her on Twitter at @MariahWoelfel.