Increases in special-education costs in Pennsylvania are far outpacing increases in the state's contributions to those expenses, leaving local school districts to pick up bigger shares of the tabs, according to a report released Tuesday.

While state aid for special education increased by $72 million between 2008 and 2016, district special-education costs grew by $1.54 billion, according to the report by the Education Law Center and PA Schools Work. For every additional $1 provided by the state, school districts allocated $20, the report said.

"Despite recent state investments, the state's special education funding is becoming more inadequate and inequitable," said Reynelle Brown Staley, policy attorney for the law center. "There is simply not enough money coming from the state in either the basic-education or special-education line items."

The report comes amid an ongoing lawsuit challenging how Pennsylvania pays for public education. The suit — brought in part by the law center — alleges that the system is inadequate and discriminates against children in poorer communities that cannot keep up with rising costs.

Those poorer districts are "particularly ill-equipped to provide students with disabilities" the education to which they are legally entitled, according to the report. It said the widening divide between special-education costs and state funding "forces local school boards to choose between raising additional revenue to meet funding gaps, spreading limited resources across a range of programs, and/or reducing needed services and supports for students with disabilities."

Jay Himes, executive director of the Pennsylvania Association of School Business Officials, said some school districts have reduced resources for regular education programs in order to pay for required special-education expenses.

"It's a double whammy of federal and state mandates," Himes said. "You don't cut costs, you try to manage your costs."

Special-education funding has also been a challenge in New Jersey. School districts there recently reported that it constituted 22 percent of their budgets, up from 13 percent in 2006-07, according to the New Jersey Association of School Business Officials. New Jersey directs money to school districts based on the statewide average of students requiring special-education services.

Pennsylvania has a different approach. Lawmakers in 2014 adopted a formula that directed money to districts based on the number of students receiving special education and the severity of their needs. As with the state's formula for paying for regular education, however, the approach applied only to new spending.

Despite the new formula, "we were still hearing concerns from students and families across Pennsylvania," Staley said. The amount of money added by the state "simply wasn't enough" to keep pace with district needs, she said.

On average, special-education costs increased by 5 percent each year between 2008 and 2016, Staley said. In some districts, however, costs grew at a much more rapid pace.

In Upper Darby, special-education costs more than doubled, rising from $20 million in 2008 to $42 million in 2016, while the state share of those costs fell from 35 percent to 18 percent. Philadelphia's special-education costs nearly doubled during those years — from $304 million to $598 million — while the state share dropped from 42 percent to 23 percent.

“Our special education costs have risen exponentially while state aid for special education has increased marginally,” said Uri Monson, the district’s chief financial officer.

The law center didn't analyze the reasons for the cost increases.

Himes said that "by federal mandate, the process certainly gives parents a lot of rights in seeking whatever services they need are necessary for their children and students." He said that while the numbers of students might be a driver in the cost increases, "I think it's more about the cost of services, and seeking very, very specialized and hence, high-cost services."

Advocates said providing more state money for special-education would benefit not just students but the state. "They're going to be more employable, and they're going to need less publicly funded supports later," said Maureen Cronin, executive director of the Arc of Pennsylvania. for Pennsylvania, "it will save money in their adult system."