The need for a neuropsychological evaluation in qualifying for testing accommodations depends on the type of testing accommodation and the tests that it is being used for. For some accommodations and for some standardized tests, it is possible to qualify for the accommodations by simply showing that the student is already receiving those accommodations in their school. However, for many tests, the administering company (i.e., Pearson, College Board, State Agency) requires medical/clinical documentation that demonstrates the need for the accommodations. This is where it can be essential to have a neuropsychological evaluation report to prove the need for the accommodation.
This is especially true when the student is requesting extra time for a difficulty with reading or ADHD. As these types of disorders do not have visible medical markers, testing companies will often require more than a letter or a previous diagnosis to grant the accommodation request.