A federal judge has ordered Washington, D.C. to intensify its efforts to find, assess and treat students with special needs.

U.S. District Judge Royce C. Lamberth said that the city had failed to provide services to hundreds of eligible preschoolers, and found that parents ran into delays and blocks while trying to get services their children were entitled to under federal law.

Lamberth’s ruling was issued in response to a class-action suit filed in 2005 by the parents of seven children. The judge’s order set performance benchmarks for special education officials and will result in stricter measures—including the possible appointment of a special master—if the city fails to meet the new standards.

The city will be required to make sure that 95 percent of preschool children referred for special services are evaluated within 120 days, and that children in early intervention programs receive the proper assistance to allow them to transition to preschool special education programs by age 3.