In Arlington Central School District v. Murphy, SCOTUS considered whether the Individuals with Disabilities Education Act ("IDEA"), which provides that a court "may award reasonable attorneys' fees as part of the costs" to parents who prevail in an action brought under the Act, also authorizes prevailing parents to recover fees for services rendered by experts. SCOTUS based its decision on the Spending Clause. When Congress attaches conditions to acceptance of federal funds, the conditions must be set out unambiguously. States cannot knowingly accept conditions of which they are "unaware" or which they are "unable to ascertain."
In examining the words of the statue, SCOTUS held that costs is a term of art that generally does not include expert fees--unlike the term "expenses" which is much broader. Hence, the statutory language does not support the payment of expert fees and even if that were an intended result of this congressional legislation, the States did not receive clear notice under the Spending Clause of the condition.