A major error turned away thousands of students who qualified for gifted and talented programs in city public schools.
Pearson Publishing said it incorrectly told nearly 5,000 students they did not score high enough to qualify for the special classes, when, in fact, they had.
The New York City Department of Education said the errors were first noticed by parents.
Pearson has issued an apology to parents and the DOE, and said it will conduct a full investigation into the mishap.
Schools Chancellor Dennis Walcott responded with a statement.
"Pearson has an established record in the field, but in this case, they let our children and families down," Walcott's statement reads. "I have told the company's officials in no uncertain terms that I expect this will never happen again."
Deadlines for enrolling in gifted classes have been extended, and the DOE said they will inform families whether their children's scores were affected by the error.