Barbara Robertson moved to Chester County to live closer to her daughter.

Robertson and her husband, who are in their 80s, left Montgomery County and settled into a home in the Villages at Hillview, a 55-and-older community in Valley Township.

There’s just one problem: The annual school district tax bill for their home is nearly $6,500, after the Coatesville Area School District board approved a 3.9% increase for the 2019-20 school year. In the six years they have owned the house, school taxes have increased more than 20%, and their district’s tax rates are among the highest in the region.

“I’m just fed up with it,” Robertson said Monday, after attending a hearing on education funding hosted by state lawmakers in Coatesville. “I’m ready to go back to the house I left.”

The Robertsons are among hundreds of thousands of homeowners in the Philadelphia region who have learned to expect regular school-tax increases. In all, 53 of 60 school districts in Bucks, Montgomery, Chester, and Delaware Counties have raised taxes for the 2019-20 fiscal year, according to an Inquirer analysis.

The average increase is about $100 per household, or 2%, and continues a trend. In the last 10 years, on average, taxes have risen close to $1,000 per household, or nearly 25%, The Inquirer’s analysis showed. Increases in 48 school districts have exceeded the rate of inflation; rates were double inflation in eight districts.

School officials say they are waging a constant battle against rising expenses, particularly for mandated costs for pensions, special-education programs, and charter-school payments.

School taxes in Pennsylvania make up the largest share of property-tax bills; counties and municipalities also levy property taxes, but at lower rates than school districts. Compared with other states, Pennsylvania relies more heavily on local property taxes to fund its schools. And those taxes are often unpopular — especially among seniors living on fixed incomes.

For the new school year, some of the region’s wealthiest districts with the highest-achieving schools — such as Colonial and Tredyffrin/Easttown — have enacted the largest tax increases.

Pattye Benson has been tracking tax rates in the Tredyffrin/Easttown School District for the last 15 years. There’s been an increase every year, she said; the 2019-20 budget includes a 3.9% tax hike.

Benson, of Tredyffrin Township, has one grown child who attended private school. The school portion of her property-tax bill will be more than $11,000 next year, according to property records. She said she worries about a lack of scrutiny of the school budget and its rising taxes because so many residents move to the district so they can send their children to its high-performing schools.

“There are some who are inclined not to be concerned about the taxes that are being paid, because they feel like the value they get offsets that,” she said. “But I think part of the problem is that as a result of people moving here for the school district, ... the budget process is not scrutinized as much as it would be.”

At the other end of the wealth scale, Morrisville Borough School District in Bucks County has the largest annual tax increase in the region, 6.3%. Bob Bruchak, Morrisville’s business manager, said rising special-education and charter-school costs have forced tax hikes.

From the 2015-16 to 2018-19 school year, Bruchak said, charter-school costs nearly doubled, from $589,000 to more than $1 million. In that time, Morrisville’s state funding increased by less than $100,000.

"State funding has been pretty flat for us,” said Bruchak. “The increases have been nominal. … They don’t even cover the increases in pension funds.”

But school officials say they have no choice: The law requires them to pay those pension and other mandated costs.

“They have to provide them,” said Hannah Barrick, assistant executive director of the Pennsylvania Association of School Business Officials. “They can’t just decide to take a year off.”

Districts in Philadelphia’s collar counties tend to be wealthier than those in other parts of the state and thus don’t receive as much state funding.

That often results in a tough choice for school districts, Barrick said: “It’s either raise property taxes or cut programs.”

Colonial School District, which serves Conshohocken Borough and Plymouth and Whitemarsh Townships in Montgomery County, also is raising its taxes 3.9% this school year, the fourth-highest percentage in the region.

Taxes are rising in part because the district is growing, according to David Szablowski, Colonial School District’s business administrator. The 2019-20 budget includes $80 million for a new middle school; Szablowski said it is needed because the number of students in the district will grow from 5,000 to 6,000 by the middle of the next decade.

There is no shortage of families willing to foot the rising tax bills, Szablowski said.

“Our houses don’t stay on the market for more than a week,” he said.

Some districts, such as Central Bucks and Downingtown Area School District, haven’t had any tax increases in the last five years.

Downingtown controlled expenses by contracting services to minimize the money going toward pensions, said business manager David Matyas. The district also renovated its buildings to make them more energy-efficient, he said.

But avoiding tax hikes might not be possible in the future.

“We are getting to the point where we can no longer expand existing buildings and will need to construct new facilities,” Matyas wrote in an emailed statement.

Barrick, of the school business officials association, said that it’s likely most districts will have to continue regular tax increases because costs will continue to rise.

But some districts could buck that predicted trend. Szablowski remained optimistic about Colonial raising its taxes less in the future, and pointed out that the debt the school district took out to cover building its middle school will be repaid over the next two years.

“I do believe there’s an end to it,” Szablowski said. “Next year will probably be a bad year, but then every year after that we should able to get back to where we used to be.”

A previous version of this article incorrectly described the tax increase for the Unionville-Chadds Ford School District.