ROSEVILLE (CBS13) – Dozens of students are dropping their face masks at school thanks to a medical exemption.

Almost all of them are coming from just one doctor, but the school district says there’s nothing it can do about it. Parents and the district now question why so many mask exemptions are coming from one local doctor.

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The phone has been ringing off the hook at Dr. Michael Huang’s Roseville office.

“We are fully booked up for the next three months, I can definitely get you in,” his receptionist Ashley said on the phone.

They’re all looking for the same thing: a medical mask exemption.

Sources tell CBS13 at least 50 medical exemptions have been submitted at south Placer County School districts. About 85 percent of those exemptions have come from one doctor.

Dr. Huang maintains his exemptions are handed out after a physical exam.

CBS13 asked Dr. Huang whether these exemptions are legitimate and whether those students actually need mask exemptions.

“The mask exemption letter, the one we do provide, each every one of them is after careful clinical exam and given appropriately,” he said.

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Parents like Lou Foreman sought him out. He says his two Eureka School District kids have breathing issues.

“My kids today are in school, they’re not masked and they’ve been integrated into their classrooms,” he said.

But Eureka School District parent Dr. Chris Lillis worries about the immunocompromised kids in his child’s 5th-grade classroom.

“I’m exasperated because I feel like it’s such a small gesture to wear a mask to protect the health of someone who is less fortunate, and more vulnerable than we may be,” he said.

So what is a legitimate medical excuse?

From breathing problems to something more severe, the California Department of Public Health has not laid out what that means.

In fact, only Friday, the state just clarified the exemption needs to come from a doctor and not a parent. And the school district says they have no way to prove an exemption is real, saying they have no choice but to accept the document and let these kids go maskless.

“So school administrators, teachers, they’re not in a position to question medical diagnoses, but they are required to follow guidance, which requires masks in the classroom,” said Michelle Eklund, Chief Communications Officer with the Placer County Office of Education.

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The district says an exemption from a medical doctor is valid until proven otherwise and would require the state medical board to review the child’s medical records—something that could take months.