Boston Public Schools plans to spend at least $1.139 billion in the next fiscal year, a $26 million increase over this year’s budget. District officials have touted the 2020 budget as “the largest ever” — as they do every year.

And owing to the way funds are distributed, many schools can expect either limited new investment or cuts for the next year. That said, there is some genuine change afoot in the district’s central office. Budget officials say they’ve developed a way to ease the pain for schools facing cuts.

And for the first time, both Mayor Marty Walsh and the district superintendent have thrown their explicit support behind a sweeping effort to boost state aid for schools.

It may not count as headline news that Boston is spending “historic” amounts on public schools year after year.

The city’s tax base is growing quickly, as is the cost of providing health benefits, for example. And the Legislature is providing for a smaller and smaller share of BPS’s overall expenses.

Still, the increase is impressive when tracked over a longer period of time.

When Walsh took office in 2014, BPS spent $16,500 for each of its students. It expects to spend $20,700 in the next fiscal year. That’s an increase of more than 25 percent over six years.

Eleanor Laurans, the BPS budget chief, attributed much of that growth to the rising cost of the district’s workforce, from contractual pay increases to more expensive benefits. (The district is currently negotiating with its teachers’ union and expects its spending to exceed $1.14 billion for that reason.)

The rest, she said, has gone to “important investments,” especially early-childhood education, a new hiring initiative, and a longer school day, all of which she said have proven to be effective.

Some — including Paul Grogan, president of the nonprofit Boston Foundation — have warned that the district’s teaching force is becoming too expensive since at least 2011, when the average annual salary for a BPS teacher was around $83,000. (By last year, it had risen to nearly $100,000, according to state data.)

BPS relies on a system called “weighted student funding,” or WSF, to distribute funds in its budgets. WSF apportions funding based on a school’s student body, with particular increments applied depending on how many of those students have disabilities or language needs, for example. So, when a school’s enrollment shrinks or changes, it can expect a hit to its operating budget for the year ahead.

For that reason, growing investment across the district doesn’t mean that every school has enjoyed new investment. Far from it, argued Kristin Johnson, a BPS parent and activist. “Every year [enrollment-related cuts] send a number of schools into chaos,” she said, adding that includes the BTU Pilot School in Jamaica Plain, where her child is a student.

Nationally, WSF has won praise from school reformers who see it as a means to optimize (and trim) education spending in complex urban districts. But like other activists, Johnson took issue with what she called its “Darwinist” logic.

Under WSF, Johnson said, “Enrollments go down, we lose programming and teachers. We lose more students. We lose more programming. It’s death by a thousand budget cuts.”

In this proposed budget, the district will try to slow that downward spiral.

Interim Superintendent Laura Perille described a new $6 million “soft landing” program. It would represent a rebate to schools suffering large losses amounting to 2 percent of their overall budget.

“Small shifts in enrollment — at small schools — can have a very dramatic impact,” Perille said. “We support the principle of weighted student funding, but we’ll protect schools and buffer them a little bit from the year-to-year enrollment shifts.”

Since 2015, Sen. Sonia Chang-Diaz — who lives in Jamaica Plain — has raised louder and louder complaints about the state’s failure to adequately fund public schools, especially in the neediest districts.

But city and district officials in Boston have largely kept mum about a legislative change. Instead, Walsh and others have complained the state has failed to adequately fund its existing commitments, especially its long-neglected plan to temporarily reimburse districts like Boston who lose many students each year to charter schools.

That changed in January, when Chang-Diaz announced a new version of her bill with Walsh’s backing.

The new bill, known as the “Education PROMISE Act,” would still give more funds to the state’s neediest districts. But it would also ensure that districts with many charter school students get at least the minimum state aid they’re promised under state law.

Perille and Laurans, too, spoke out in support of the PROMISE Act, with Perille saying state support “has to be part of the conversation.”

Max Larkin is a multimedia reporter for Edify on WBUR 90.9FM, which is a partner of the Dorchester Reporter. This story first appeared on the WBUR website on Feb. 6.