Every school system needs substitute teachers, but in recent years there has been a shortage in the suburbs of Maryland. So when classrooms lacked a teacher, administrators would scramble, filling the gap with another educator at their school.

In Montgomery County, an average of 120 substitute teacher requests went unfilled each day.

But for the coming school year, which begins Tuesday, that could change in the state’s largest school system.

Hoping to broaden the pool of substitute teachers, school system officials have reduced requirements for the job: No longer is a bachelor’s degree the minimum. Now, applicants can qualify with an associate degree or 60 college credits.

“It will make a big difference,” said Jeanette Dixon, the school board member who urged the issue be taken up. Not only will it help schools cover classes when teachers are absent, it will ease the burden on other educators who have their own work and have to unexpectedly shift course, she said.

“Hopefully, after careful screening, we will get some good candidates and even some people who will be inspired to pursue a teaching career,” she said, predicting that the move could also help diversify the workforce.

School system officials underscored that Montgomery had previously set a higher bar in its qualifications than eight nearby school systems.

Several of those systems rely on minimum requirements of 60 credits — including Prince George’s County and Virginia’s Fairfax County — while others require 48 or 30 credits. Charles County, in southern Maryland, requires a high school diploma for daily substitutes and a four-year college degree for “long-term substitutes,” who fill in for 16 days or more.

Andrew Zuckerman, chief operating officer for the Montgomery school system, told the school board in July that a comparison showed Montgomery was expecting more than its counterparts, calling the differences “quite glaring and eye-opening.”

In Montgomery, the school system’s roster includes more than 3,000 substitute teachers. An average of about 500 to 600 requests a day pour in for substitutes to work at its more than 200 schools. Not all substitutes are available every day, and some have geographic or other constraints.

Thus, the shortage.

“Obviously, we were not in sync with what other districts do to increase the pool of subs,” school board vice president Patricia O’Neill said.

Ryan D. Forkert, principal of Luxmanor Elementary School, said the need for substitutes tends to be low during the early part of the school year, but as the academic year progresses, his school in Rockville may need a substitute in one class or another four days in a week.

If no substitute is available — about 15 percent of the time — other educators at the school are tapped: perhaps a reading specialist, a counselor, a staff development teacher or an instructional assistant, he said.

“When we pull them to cover the class, it takes away from what they are doing,” Forkert said.

Teachers can be away from their classrooms for a range of reasons — sicknesses, doctors’ appointments, professional trai­ning, family emergencies.

But the substitute shortage can become a particular issue during cold and flu season, when more teachers are out, said Shahid Muhammad, principal of Forest Oak Middle School in Gaithersburg.

“It’s a scramble,” he said. “If you’re doing that multiple times during the week, it can be a strain on the teachers who deliver instructions.”

School officials said having more people to draw on — and fewer unfilled requests — was widely supported when they sought comment. They consulted school-based staff members, parents, students and union leaders, they said.

Still, some have noted drawbacks.

Christopher Lloyd, president of the Montgomery County Education Association, the teachers union, pointed to the importance of education and training for teachers.

“While we hope the new requirements will help with the sub pool, we’re also concerned that in a time when the state is trying to raise standards for being a teacher, this lowers that bar for guest teachers,” he said.

School officials say substitute teachers must undergo background checks and an interview screening process before they are hired. Pay starts at $19.58 an hour for those who are certified and $18.41 an hour for those who are not.

About 10 percent of Montgomery’s substitutes are retired county teachers. In a broad sense, substitute teachers fill in for teachers who are absent, presiding over their classes and carrying out their lesson plans.

The idea of revisiting the qualifications of substitute teachers followed a school board meeting at Paint Branch High School in March, when a parent approached Dixon and said, as she recalls, “I have a two-year associate degree. I would love to substitute.”

“I thought, ‘Oh, this is a great idea,’ ” Dixon said.

In March, the school board passed a resolution asking for a review of the issue. The findings were presented at a July board meeting. The change was made administratively, without a board vote.

Montgomery has already fielded more than 20 applications from job candidates with an associate degree or less, a spokesman said, and is kicking off an effort to spark broader interest.

Superintendent Jack Smith told the board he saw the shift as an opportunity to bring in Montgomery residents “who have talents, skills, intellect, abilities but maybe didn’t get a chance to get a bachelor’s degree.”