FOUR YEARS AFTER a state commission declared that the Massachusetts education funding formula was shortchanging school districts by $1 to $2 billion, state lawmakers unveiled an ambitious proposal that would increase state aid to local schools by $1.4 billion.

The bill goes a long way toward meeting the calls of education advocates and district leaders to significantly increase funding for schools, especially those educating high concentrations of low-income students.

“While we are all proud of Massachusetts’ top rating nationally in education, we want to extend that success to all students,” said House Speaker Robert DeLeo at a briefing on the legislation Thursday morning. The bill, he said, “will close the opportunity gap” facing more disadvantaged students. 

Senate President Karen Spilka, citing her long involvement in education, including as a parent and former school committee member, called it “a momentous day” for the state.

DeLeo said the funding increases, to be ramped up over seven years, could be achieved without new taxes.

The long-awaited announcement, which came after months of behind-the-scenes negotiations between leaders of the Legislature’s education committee, will set in motion public debate on Beacon Hill on an issue identified by legislative leaders and Gov. Charlie Baker as a top priority of the current legislative session.

DeLeo and Spilka briefed reporters on the legislation together with the education committee co-chairs, Rep. Alice Peisch and Sen. Jason Lewis.

Along with the substantial $1.4 billion increase in state aid to schools, the bill earmarks a further $100 million in education spending, including an increase in funding for out-of-district transportation costs for special education students and setting a three-year timeline for fully funding a reimbursement formula for districts that lose students to charter schools. The bill also would establish a $10 million trust fund to support innovative approaches by school districts to student learning and school improvement, and calls for a system for districts to set targets for closing achievement gaps and publicly report on their progress.

School construction would be helped by an increase in the annual spending cap for the Massachusetts School Building Authority from $600 million to $750 million.

Peisch said the legislation would make “an unprecedented” investment in public education, which is likely to reach $2 billion after accounting for inflation. The state currently devotes $5.1 billion to local school aid. She said state leaders have been “painfully aware” of gaps in achievement — as well as funding — plaguing districts with lots of low-income students.

Lewis said if the bill is passed, “we will have the strongest, most progressive education funding system in terms of how we reflect the needs of low income students.”

The proposal, dubbed the Student Opportunity Act, would be the biggest overhaul of the state’s school financing law since passage 26 years ago of the landmark Education Reform Act. The 1993 law led to a dramatic increase in state funding for local districts, with much of the new spending targeted to lower-income communities. It was paired with rigorous new curriculum standards and a state accountability system aimed at driving gains in student achievement, particularly among lower-performing students. 

In 2015, a bipartisan commission concluded that the formula laid out in the 1993 law to fund local districts had not kept pace with rising costs in four main areas. The commission was clear in identifying the shortfall in funding for employee health care costs, special education services, and English language learner services. But the panel did not settle on how much funding should be increased for serving low-income students, instead recommending that districts with the highest concentration of low-income students receive anywhere from 50 percent to 100 percent more than the base rate for each such student. 

The bill unveiled Thursday lands at the upper end of that range, recommending a 100 percent increase over the base funding level for low-income students in districts with the highest concentrations of poverty.

“This is a gigantic development in terms of moving the equity agenda forward here,” said former state education secretary Paul Reville, who now teaches at the Harvard Graduate School of Education. “And it does so thoughtfully and in a way that has some checks and balances to it.”

The state’s complicated formula for determining a “foundation budget” is meant to establish the minimum amount of per pupil spending necessary to provide all students with an adequate education. On top of a base amount — currently about $8,000 per year — the formula includes additional funds to educate student groups in need of more services, such as English learners and low-income students.

The state also establishes a breakdown of the share of foundation budget spending that must be funded by local communities and the share to be paid by the state, with wealthier cities and towns responsible for a greater share.

The bill creates a huge gulf between the Legislature and Baker administration in funding plans for schools. The governor filed a funding reform bill in January that would boost state aid to districts by about $460 million, or almost $1 billion less than the proposal rolled out by lawmakers.

Baker warned in an op-ed earlier this week in the Boston Globe that bigger increases in state aid would require communities to significantly increase local school spending and could require property tax increases.

Baker offered a guarded reaction to the proposal from the Legislature.

“The administration appreciates the Legislature’s work to propose the Student Opportunity Act and will carefully review the bill to evaluate the fiscal impact, effect on municipal finance and ability to improve our schools for every kid,” said Lizzy Guyton, Baker’s communications director, in a statement.

But the bill was widely praised by broad range of education stakeholders and advocates.

Sen. Sonia Chang-Diaz, the former education committee co-chair and lead sponsor of one of the main funding bills the committee considered in crafting the legislation, hailed the proposal. “This is what momentous, generational progress looks like in education and economic justice,” she said. The bill appears to track closely the increases her bill called for in funding for low-income students.

The Massachusetts Teachers Association, the state’s largest teachers union, said the bill “helps every district and advances the causes of equity and justice for the districts most in need.”

It also got positive reviews from Democrats for Education Reform and Massachusetts Parents United, two groups that have tangled with teachers unions.

“This bill is a win for kids around the state: more money, strong safeguards, and a renewed commitment to education,” said Liam Kerr, director of DFER’s Massachusetts chapter.

Edward Lambert, director of the Massachusetts Business Alliance for Education, said he was particularly encouraged by the provision requiring districts to establish clear improvement targets to accompany the new funding. “That’s a big win for those of us who have been advocating for some guardrails and strings, if that’s what you want to call them, as to how the money is going to be spent and where it’s going to be spent,” he said.

Reville, the former education secretary, said it will be crucial that the state education department be given the resources to oversee the district plans. “It doesn’t have a dozen people hanging around now who are able to do that kind of work and just drop whatever they’re doing,” he said.

Lambert said as the bill moves forward he would like to see incentives added for schools to redesign their programming to have students better prepared for college and careers. “We know scores of kids are graduating from high school and flaming out in college or finding they don’t have the career skills they need,” he said.

Baker’s bill would incorporate a new element in the state formula to fund students enrolled in early college programs in which high school students get exposure to college settings — and begin to accrue post-secondary credits. The Student Opportunity Act doesn’t include early college funding.

The bill also does not include a provision in the bill filed by Chang-Diaz that was strongly backed by Boston Mayor Marty Walsh and would have steered millions of dollars in added funding to communities with large charter school populations. Boston would have seen as much as $100 million in added state aid through the provision.

Justin Sterritt, the city’s budget director, said that although the legislation doesn’t include that provision, the bill does “a few really key things for Boston,” including boosting the funding for low-income students and the commitment to fully fund the charter reimbursement formula, an issue distinct from the charter funding language of Chang-Diaz’s bill. He said the bill will also make a big difference to Boston because it resets the standard used to determine the population of low-income students. A 2016 change in the federal law governing subsidized school breakfast and lunch programs threw off districts’ count of their low-income population, with thousands of students dropped from the calculations.

Lewis said he anticipates that the Senate will debate the bill during the week of September 30, after which it will go to the House. He said it was not clear at this point if the bill could clear both branches or whether the House and Senate will pass differing versions that must be reconciled in a conference committee.

Lawmakers worked last year on a bill revamping the formula, but House and Senate negotiators could not reach agreement before the end of the legislative session last July. Legislative leaders and Baker vowed to make the issue a priority this year, and pressure has been mounting for state officials to approve a bill this year.

In May, mayors and school superintendents from Gateway Cities said they were prepared to file suit against the state if lawmakers did not make good on the promise to get the job done this year. Among those in the group of urban officials were leaders from Brockton, where a lawsuit first filed in the late 1970s provided some of the pressure ultimately resulting in the 1993 reform law.