Researchers design scripted supplemental mathematics programs for struggling students, such as students with learning disabilities (LD), to encourage an evidence-based presentation of concepts and use of instructional language in teachers' implementation. In practice, teachers may or may not implement these programs with high fidelity, resulting in slight to substantial curriculum alterations. Yet there is a dearth of studies detailing the nature of changes teachers make during instruction or their perceptions of why the changes were necessary. We present a qualitative analysis of 10 special educators' employment of a Base Ten Numeration and Multiplication/Division Strategies intervention with students with LD. Results show that teachers altered modeled practice and guided practice lesson components more than any other lesson component. Three interrelated themes illustrate reasons for pedagogy, materials, and tasks alterations: (a) scripted tasks/script, (b) connections, and (c) lesson delivery methods.