During the past 20 years, researchers have identified core deficits of struggling readers and developed treatments that prevent reading failure. However, whereas progress has been made toward designing generally effective reading interventions, not all children respond to these treatments. Such students have been dubbed “nonresponders,” and are the current focus of a growing body of research. Because nonresponsiveness to generally effective instruction is a relatively new issue, researchers have yet to agree on how to identify nonresponders. The purpose of this article is to propose a “dual-discrepancy” approach to identifying such children. A rationale for such an approach is given. Then, curriculum-based measurement is suggested as an effective tool for detecting dual discrepancies. An example is provided from an ongoing program of research that uses the dual-discrepancy approach to identify nonresponders.