, KSDK TV San Diego

Some California teens are giving a new meaning to "high" school.

Students are finding easy access to medical marijuana cards and presenting those cards to school authorities as a legitimate excuse for getting high.

But, where are the cards coming from?

A letter was sent home to parents of students in the Grossmont Union High School District.

"It's not a get out of jail free card at all." Catherine Martin says even though medical marijuana is legal in California, the law doesn't apply to schools which are subject to federal law. The district also says the students most recently suspended for being high with cards in hand - didn't have major illnesses.

"Students are getting them for things like sleeplessness and stress - it just draws into question how easy is it for people to get their hands on these cards."

According to the district attorney's office, it's extremely easy if you know where to look.

"The cards these kids have, I've not seen them, are issued by Doctor's offices or clinics that sell cards."

"During a series of recent under cover sting operations, DA investigators identified a handful of San Diego Doctors who prescribe marijuana to just about anyone, so long as they have a symptom and money."

One of those doctors runs a business called MediMar.

An NBC affiliate learned Dr. Kenneth Johnson of Medimar is the same doctor who signed off on at least one of the Grossmont District students.

His clinic at this Mission Valley office building was closed but down the hall a separate business was closed permanently by San Diego police.

Patients stated that you had a short consultation, came in and filled out a short questionnaire, talked to a couple guys, got a prescription and then you'd walk across the hall and get your prescription filled.