Montgomery County’s school system is diverse, but its schools are less so. Some have high poverty rates, while others are tucked into affluent enclaves of the Maryland suburbs. Many bring together large percentages of students of color, and others not as much.

But the sometimes stark differences in schools could gradually change under a step taken by the county school board this week that shifts the way boundaries are drawn, in hopes of better integrating classrooms in the system’s 206 schools. The diversity of a school’s student body will get greater weight in boundary decisions than other factors as new schools open or existing schools are evaluated.

Some see it as a defining decision in a county that prides itself on being inclusive and equity-minded and yet has struggled to narrow achievement gaps. Others raise questions about how it will play out.

“It lays the groundwork for a more equitable future for our students,” said Jill Ortman-Fouse (At Large), a school board member who pressed the issue.

The move — supported by some education advocates, parents and students — did not receive universal backing: Some objected, and the issue divided school board members, who voted 5 to 3 for the change. In recent weeks, some parents said they feared a forced busing plan was in the works. There is no discussion of that, school officials said Tuesday.

Several parents said they support diversity but not the change to boundary-drawing.

“It limits the board’s flexibility to deal with these boundary issues on a case-by-case basis,” said Jennifer Young, a longtime PTA leader in Rockville who said she found it frustrating that the issue was framed as a vote for or against diversity. “Everyone wants diversity in our schools,” she said, “but it’s a complex issue in each community.”

The debate came as Montgomery’s student enrollment — more than 163,000 this year — has surged. Largely white at one time, the student body is 32 percent Latino, 28 percent white, 21 percent African American and 14 percent Asian. The balance is made up of Native Americans, Pacific Islanders and multiracial students.

More than 56,000 students are eligible for free or reduced-price meals, a marker of need among families — a figure that has risen markedly during the past decade.

Supporters of the policy change have pointed out that high schools with the best graduation rates have relatively few economically disadvantaged students, and the schools with the lowest graduation rates have roughly five times as many. They say all students do better in diverse environments.

They cite research including a 2014 county report that showed gaps in student performance between high-poverty and better-off schools in Montgomery. It said the school system had “lost ground in achieving its racial and economic integration goals.”

“We need to make policy decisions that reflect the values that we say we have as a county,” said Lynne Harris, president of the countywide council of PTAs. “We say, ‘All means all.’ We say we want every student to get the best education. But our schools are segregated. I think we have to be more proactive.”

The emphasis on diversity comes amid an overhaul of planning for school facilities discussed since spring. The language on diversity was added Sept. 13 by the board’s policy committee and sent to the board for consideration. A previous effort in April to add similar language failed.

Under the previous policy, diversity was considered equally with other factors — neighborhood considerations, whether students had previously been reassigned and the capacity of school facilities.

The change would give diversity “a little bit more” weight than the other factors, Ortman-Fouse said at the meeting.

She said other systems review boundaries more regularly. “Somehow in Montgomery County, we came up with this notion that we don’t touch boundaries because it’s the third rail and when you buy a house, you buy a school,” Ortman-Fouse said.

Ananya Tadikonda, the board’s student member, called diversity in the district’s schools imperative.

“This is what students truly believe in,” she said, recalling a fellow student’s observation that in a county so rich with people of varied backgrounds, every student should have a chance to learn at a diverse school.

“The best thing to do for our students is to ensure they learn how to work and thrive in those environments,” she said.

Nick Asante, a Richard Montgomery High School sophomore addressing the board, recalled that in middle school, he sat down in a computer science class on the first day, only to be asked by a fellow student whether he was sure he was in the right place.

He was baffled, he said, before he realized: “I was the only African American in that room. In fact, I later found out that I was one of only two African Americans in the whole 50-person program.” Later, he said, he turned down an offer to attend a prestigious math-science magnet program. The main reason — a lack of diversity.

“I didn’t want to be in an educational environment where I stood out because of my race as opposed to my intellectual ideas and my capabilities,” he said.

He urged the board to support changing the process for drawing boundaries. “In a world full of bigotry, prejudice and ignorance, it is vital that our students are taught the importance of accepting the differences of others,” he said.

Board member Patricia O’Neill (District 3) said “no perfect answer” exists for increasing diversity, because the school system does not control housing policy or other factors, but she supported the change.

After the meeting, she predicted challenging times ahead.

“No boundary decision is ever easy,” she said. “The board just has to have thick skin and the will to do the right thing.”

Michael A. Durso (District 5), the school board president, voted against the change. He said he had practical, operational concerns. “We’re looking for a fairly easy solution to a complex problem,” he said.

The diversity of schools became a flash point last year, when the school system was preparing to open a new elementary school in a Rockville community with schools of varied poverty rates. Debate was heated as some pushed for greater diversity at all elementary schools in the community and more balance at the high-poverty school, Twinbrook Elementary. In the end, families at Twinbrook stayed put.

“It struck our families as a lot of social engineering,” said Vincent Russo, then the PTA president. “They felt their kids were going to be sprinkled around the cluster to make the numbers balance out. It came off as kind of patronizing.”