Imagine a current HMO that covered only the procedures and diseases recognized by the medical profession in 1950. The thought is ridiculous because in such a rapidly developing field as medicine, no one would expect practice to be frozen at the level of scientific knowledge attained 50 years ago. The author believes this is what has happened in the field of Learning Disability (LD), in a less extreme fashion. He asserts that the field suffers greatly from its tendency to base practice on concepts and psychometric technologies that have been superseded by subsequent scientific advance. He is referring here to the field's persistence in linking the definition of learning disability to the concept of aptitude-achievement discrepancy and identifying aptitude with intelligence test performance. In this article, the author evaluates the issues surrounding reading disability, the most common type of learning disability, and the one where his expertise is concentrated.