A $100,000 deficit in the 2011-12 budget announced at the Board of Education meeting earlier this month may not bear the cost to Wilton that it implies.

Although there was a deficit in the school district's operating budget, there ended up being an effective surplus six times greater.

According to Ken Post, town director of financial planning and operations, the school board ended up with a net surplus of roughly $640,000 after receiving $740,531 from the state to cover overspending for students with special needs.

If a school needs to spend 4.5 times more on a student than expected in the budget proposal, the state must reimburse the costs, Mr. Post said.

That threshold for per-student spending was estimated at about $70,500; individual student costs were expected to be about $17,500.

There was a significant reimbursement because expenses for 24 students crossed that threshold at high excess. Special-needs costs were the primary driver, resulting mostly from contracted services, with more students than anticipated needing evaluations, especially those diagnosed as hearing impaired.

Special-needs evaluations are often lengthy processes involving a planning and placement team comprising parents, administrators and teachers.

The higher-than-expected number of cases of children with hearing difficulties was the board's reason behind hiring a districtwide staff member who specializes in hearing disabilities in the current budget.

Although the operating deficit was mostly due to overspending on special needs, there was also an unexpectedly high number of health insurance claims.

"We had been running a little high for most of the year, but the claims really jumped up in the last month," Mr. Post said. "We also had more people than normal with very high claims."

Claims did not reach the stop-loss insurance of $225,000, which would have merited financial aid from Anthem, the school's insurance company.

The school's reserve fund helped cover the claims, which had enough saved to handle the health care costs.

Legal fees were also higher, which stemmed from parents filing more claims that their children are not receiving an adequate public school education. These claims are handled at the state level.

"In general, parents can file a due process claim if they feel our program is not providing a free, appropriate education," Mr. Post said.

The effective 2011-12 net surplus will go toward operating revenue at the end of the year.

For information on school board budgets, visit wilton.k12.ct.us/pages/Wilton_School_District.