SOUTH BEND, Ind. >> In the last two years, a northern Indiana high school sold the naming rights to its football field to a bank for $400,000, its baseball field to an auto dealership, its softball field to a law firm, its tennis court to a philanthropic couple and its concession stands to a tire and auto care company and a restaurant.

Even music rooms in the district’s 11 elementary schools were named for a couple who donated more than $50,000 over 10 years. All told, the nonprofit Penn-Harris-Madison Education Foundation has signed agreements that will bring the district more than $600,000 in the coming years — and school officials are looking for more.

An idea that started with professional sports teams and worked its way through colleges and universities has taken root in public schools around the U.S. as funding for districts tightens for various reasons, including political fights, tax cuts and property tax caps.

“I see this as kind of a logical progression,” said Josh Boyd, an associate professor at Purdue University’s Brian Lamb School of Communication who has researched naming rights. “It’s not surprising we’re seeing the next level down in athletics doing the same thing. But I think it’s still in the early stages.”

The goal of the Penn-Harris-Madison School Corporation in Mishawaka, Indiana, about 10 miles from South Bend, is to build a $4 million endowment similar to those at universities, ensuring a steady, dependable stream of income for additional teacher training and programs for students, Superintendent Jerry Thacker said.

“We think that money will separate us from doing good things to doing great things,” he said.

But Jeff Bertoni, the president of Market Street Sports Group, which started 10 years ago to help Pennsylvania schools find sponsorship money, said most districts are aiming lower than that.

“A typical district may bring in a couple hundred thousand dollars extra a year. But for these districts, that extra couple hundred thousand dollars a year saves programs,” said Bertoni, whose company works with 10 school districts.

Often, naming rights and sports go hand-in-hand.

Westfield Washington Schools, a district about 25 miles north of Indianapolis, agreed in 2014 to a 10-year, $1.2 million naming rights deal with a health care provider to help build a 5,000-seat high school football stadium. “We wanted to build a new stadium and we didn’t want to go to taxpayers,” said Nick Verhoff, the district’s director of business and operations.

In Riverside, a western suburb of Chicago, school superintendent Kevin Skinkis read a story about schools in Texas selling naming rights and decided to see whether that would work for an $8 million renovation of Brookfield High School’s outdoor athletic complex.

“School funding in Illinois, every dollar counts, and if we could find a way to lessen the burden on the taxpayer, we thought that would be a fiscally responsible way to proceed,” he said.

The school district placed ads and contacted businesses. Jerry Kennelly bought the rights in a 20-year, $140,000 deal and named the complex after his great-uncle Martin Kennelly, who served as mayor of Chicago from 1947 to 1955.

Another suburban Chicago school district voted in March to postpone the introduction of a policy that would have exchanged naming rights at high schools in Highland Park and Deerfield to those “who have contributed a substantial sum.” Board member Debbie Hymen said she opposes selling naming rights on principle.

“I do believe that if people in their hearts believe in donating to education, they will do that,” she said. “If the only reason they are donating to education is to put their name on something, that goes against what our philosophy is.

“It’s not putting students first.”

The Aspen, Colorado, school board is surveying community members regarding a proposal by a nonprofit fundraising arm to recognize donors for contributions. Executive Director Brooke Bedingfield said the organization has a $238,000 endowment and would like to raise it to $15 million to pay for capital needs and educational programs, saying such recognition “is a common way to honor people or recognize people when they contribute to a nonprofit.”

Back in Indiana, Thacker says that even with all the rights the district has sold, there’s plenty of room to grow.

“We have a parking lot we could name, the middle school gymnasiums, every single classroom could be supported by some organization,” he said.