The Montgomery County Board of Education and the union representing the county’s 12,000 teachers have reached a tentative deal on a contract granting raises totaling about 5.5 percent over three years, school officials announced Saturday.

The yet-to-be-ratified contract, which would take effect in the 2015 fiscal year, also implements a new program to lure the system’s most effective teachers to high-needs schools and makes student feedback part of the yearly evaluation process.

In total, the raises amount to $35.8 million in extra costs for the county, an amount offset partially by higher health-insurance premium payments agreed to by the union, both sides said.

Identical contracts for school principals, administrators and support staffers are in the final negotiation stages, said Dana Tofig, spokesman for the public school system, which serves about 150,000 students.

“It’s very fair to say that they’re close to an agreement,” Tofig said of the other pending contracts.

Under the teachers’ contract, instructors would get a salary increase of 1.5 percent in November, officials said. They would then get raises of 2 percent in 2015 and 2016.

The teachers’ health-insurance premiums would increase by 7 percent over the next two years, which school officials said would lead to savings totaling $23.5 million for the school system.

A new “Career Lattice” program would reward veteran teachers who commit to teaching in high-needs schools, said Tom Israel, director of the Montgomery County Education Association. Starting in the fall, that program will include 57 schools in areas of the county with the highest rates of poverty, he said.

Israel said the union is pleased by the terms of the tentative contract, which took several months to negotiate. An online vote to ratify the deal will occur during the next few weeks, ending in early March, he said.

Israel highlighted the fact that student feedback will play an important role in annual teacher evaluations, which he called an effective gauge for performance.

“We’ve got to work out all the details on it still, but the board and the teachers union are committed to creating that kind of system,” he said.

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