Officials at the U.S. Department of Education are raising concerns that school districts are inappropriately holding up or preventing evaluations of kids who may have disabilities.

In a notice sent to state education leaders across the country this spring, the federal agency said that it is worried that some schools “may be using response to intervention (RTI) strategies to delay or deny a timely initial evaluation for preschool children suspected of having a disability.”

That is problematic, the Education Department said, because the Individuals with Disabilities Education Act requires that states and school districts ensure that all children needing special education services are flagged.

“It is critical that this identification occurs in a timely manner and that no procedures or practices result in delaying or denying this identification,” the memo states.

RTI is an approach that relies on monitoring and rapidly responding to a child’s needs with a variety of interventions to help keep kids from falling behind.

“Many (local educational agencies) and preschool programs have implemented successful RTI strategies, thus ensuring that children who do not respond to interventions and are potentially eligible for special education and related services are referred for evaluation,” acknowledges the informal guidance from the Education Department.

“The IDEA, however, does not require, or encourage, (a local educational agency) or preschool program to use an RTI approach prior to a referral for evaluation or as part of determining whether a 3-, 4- or 5-year old is eligible for special education and related services.”

If a child is referred by their preschool because a disability is suspected, school districts have an obligation to initiate the evaluation process, the Education Department said. Typically, schools must conduct an initial evaluation within 60 days of receiving parent consent.

Districts can decline to evaluate a child if they do not suspect a disability, but they must explain that decision in writing. However, schools cannot decline to act on a referral in order to wait for RTI strategies to be implemented first, the agency said.

In light of these concerns, the Education Department has asked states and school districts to examine their policies and procedures for responding to evaluation referrals.

Parents who believe that a needed evaluation is being delayed while RTI strategies are attempted can file a state complaint or a due process complaint, the memo indicates.

This isn’t the first time that the Education Department has warned school districts on using RTI to delay evaluations. A 2011 letter to state directors of special education also emphasized that evaluations should proceed whether or not RTI has been attempted.