In the evolving landscape of financial literacy in education, this study aims to describe methodologies used in mathematics and special education research, specifically targeting individuals with intellectual and developmental disabilities (IDD). Based on a systematic review of research studies that addressed financial literacy for students with IDD, we analyzed definitions of financial literacy, educational objectives, and the differing strategies employed to meet those objectives and aligned target domains in financial literacy using Bloom's taxonomy. Our investigation reveals disciplinary differences in definitions, objectives, and strategies in studies from mathematics and special education. Mathematics education research encourages contextual problem-solving, urging students to apply learned knowledge to practical situations, thereby facilitating advanced financial decision-making skills. In a complementary view, special education research tends to focus on skill acquisition and maintenance that support student performance of essential financial tasks (identifying coins and their value). Both disciplines aim to enhance students' financial literacy, catering to the complex needs of individuals with IDD. This analysis underscores the need for an integrated approach to reinforce financial literacy and to promote more independent and community-involved experiences for individuals with IDD.