Word problem solving skills include complex skills. Teaching word problem solving skills to students with disabilities is more difficult compared to their peers with typical development. Therefore, effective interventions need to be determined in order to teach these skills to students with disabilities. The purpose of this study is to analyze the single-case experimental design studies that used schema-based instruction and modified schema-based instruction in the mathematical word problem-solving skills of students with disabilities. The methodological quality of studies was evaluated using the What Works Clearinghouse Single- Case Design Standards and quality of methodological rigor using quality indicators recommended by Horner et al. A total of 11 studies and 39 students with disabilities met the inclusion criteria. Nonoverlap of All Pairs (NAP) was used to report intervention effects. The weighted aggregated NAP was 97% (95% Confidence Interval (CI) = [84.7%, 100%]) for schema-based instruction and 99% (95% CI = [83.8%, 100%]) for modified schema-based instruction. Schema-based instruction is an evidence-based practice and modified schema-based instruction is an emergent evidence-based practice for mathematical word problem- solving skills of students with disabilities