In this review, we explore the extent to which researchers evaluating the efficacy of Tier 2 elementary reading interventions within the framework of Response to Intervention reported on fidelity of implementation and alignment of instruction between tiers. A literature search identified 22 empirical studies from which conclusions were drawn. Results suggest that fidelity of implementation is typically monitored at Tier 2 and that alignment between tiers of intervention is often apparent yet not explicitly stated. However, researchers frequently neglect to report on fidelity of intervention in Tier 1, potentially limiting claims that can be made about the efficacy of subsequent Tier 2 intervention. Limitations and implications for future research are discussed. (Contains 2 tables.)