Maryland education leaders on Tuesday approved the most sweeping changes in decades to state discipline policies, culminating a four-year effort to find a more constructive approach to student punishment, end racial disparities in suspensions and keep students who are punished in school.

The new regulations allow principals to suspend students but establish a more rehabilitative philosophy and reserve the harshest penalties for the most severe offenses. They also create a new timeline for appeals and add educational services for suspended students.

The Maryland State Board of Education’s action comes three weeks after Obama administration officials called for a similar rethinking of student discipline nationwide and issued the first set of federal discipline guidelines. It also follows several cases in and near the Washington region that got the attention of Maryland officials, including the suicide of a Virginia football player who had faced harsh punishment and the discipline of two Maryland lacrosse players over equipment they carried to fix their gear.

Local school boards in Maryland will have until the beginning of the next school year to revise their discipline policies. They may choose their own approaches, but the state plans to monitor the impact of discipline on minorities and special education students, and individual ­cases could end up with the board on appeal. State officials also have encouraged Maryland’s 24 districts to evaluate discipline on a case-by-case basis and to abandon zero-tolerance practices.

“I think school systems want to engage in this work,” state board President Charlene M. Dukes said. “I believe they understand how important it is to keep students in school engaged in a positive way with the academic and educational environment.”

Casey Edsall, left, and Graham Dennis were suspended in 2011 for carrying items in their gear bags that they said they used to fix their equipment. One student had a pocket knife and a Leatherman, and the other a lighter. The board threw the suspensions out. (Kim Hairston/The Baltimore Sun)

Board members said school safety remains a priority as they strive to keep students in school and help them learn from mistakes.

But the state’s largest teachers union says the new approach doesn’t address the root causes of misbehavior or provide funding for professional training, student programs or other supports. They also said the regulations could lead to an increase in disruptive students in class.

“We would like students to be in school, but at the same time, if you have a student who is disrupting other students, you have to do something about it,” said Betty Weller, president of the Maryland State Education Association.

As the board heard testimony during the past several years, thousands of public comments poured in, including many that were critical of the guidelines. One educator wrote in 2012: “You propose these ridiculous regulations without having any idea how they would work in, say, a challenging middle school population. You just leave all the fallout to the teachers.”

Most recently, some critics cited potential unintended consequences, such as more calls to the police from administrators who aim to avoid suspensions.

The Maryland board has issued two major reports that describe the toll of suspension, which falls hardest on minorities and students with disabilities. More than 42,000 students were suspended or expelled statewide last school year — placing them at risk for academic failure, dropping out and involvement in the justice system, experts say.

“We wanted to change the conversation,” board member James H. DeGraffenreidt Jr. said. Already, he said, the state’s attention has influenced schools: Maryland’s suspension rate dropped from 7 percent in 2010 to 5.1 percent last year.

Nationally, researchers and advocates who track discipline say Maryland is among a handful of states and large school districts at the forefront of a movement to use suspension more sparingly.

“Maryland is leading the way on the state level,” said Judith Browne Dianis, co-director of the Advancement Project, a civil rights organization. “The regulations will be a model for other states about how to put common sense back into discipline.”

For many experts, the state’s effort to tackle racial disparities stands out. Maryland’s suspension rate is 8.7 percent for African American students and about 3 percent for their white and Hispanic peers, according to an analysis of state data by the Center for Civil Rights Remedies at UCLA.

“I’m thrilled to see Maryland take the initiative,” said Dan Losen, director of the center. “It’s a major step in the right direction.”

Maryland’s board took up discipline in 2009 amid concerns about a case in Dorchester County involving a student who was expelled and spent much of the ninth grade with little school contact and no instruction.

The Maryland board turned its attention to “zero tolerance” policies in 2011, citing the suicide of a 15-year-old football player who took his life after a lengthy removal from school in Virginia. His case was profiled by The Washington Post and spurred an array of discipline changes in Fairfax County.

Later, a case from Talbot County came before the Maryland board on appeal.

Two high school lacrosse players were suspended in 2011 for carrying items in their gear bags that they said they used to fix their equipment. One student had a pocket knife and a Leatherman multipurpose tool; the other had a lighter.

In a rare reversal of student punishment, the board ordered in 2012 that the students’ records be cleared, saying that knives and lighters don’t belong at school but that “this case is about context and about the appropriate exercise of discretion.”

The regulations require local school boards to adopt policies that allow for discretion, keep students connected to school and “reflect a discipline philosophy based on the goals of fostering, teaching and acknowledging positive behavior.” The policies must “explain why and how long-term suspensions or expulsions are a last resort option.”

Perhaps reflecting anxieties about school security in the wake of the December 2012 mass shooting at an elementary school in Newtown, Conn., Maryland has had a spate of recent discipline cases that appear to be at odds with the board’s new regulations.

A 6-year-old in Montgomery County was suspended for pointing his finger like a gun. A second-grader in Anne Arundel County was suspended when he chewed a Pop-Tart-like pastry into the shape of a gun. In May, a kindergartner in Calvert County was suspended for bringing a cap gun onto his school bus.

The new regulations would not forbid such suspensions. The idea was not to be overly prescriptive but to reset broader thinking, DeGraffenreidt said: “We have not said, ‘Don’t suspend.’ We have said, ‘You have to document it and explain it.’ ”

Superintendents support the regulations passed Tuesday, said Carl Roberts, executive director of the Public School Superintendents Association of Maryland. “They believe they still have the autonomy at the local level to make wise decisions associated with student and staff safety and security,” he said.

In some areas of the state, changes already are underway.

In Prince George’s County, Daryl Williams, chief of student services, said the school system has worked with state officials and has incorporated similar thinking into its practices, with a goal of reducing expulsions and encouraging alternatives to out-of-school suspension.

“The whole idea is that we don’t want to lose that instructional time that is so vital to student success,” Williams said.

Montgomery is focused on reducing suspensions and racial disparities, said Chrisandra Richardson, an associate superintendent. “We’re not there yet, but over time suspensions have been greatly reduced,” she said.