This study synthesized intervention studies focusing on instruction to improve fraction skills. Seventeen studies met the inclusion criteria: being published in English-language peer-reviewed journals or dissertations between 1975 and 2014, and targeting 3rd- through 12th-grade students struggling to learn mathematics. From the "Common Core State Standards for Mathematics," addition and subtraction of fractions were most frequently representing the "Standards for Mathematical Content," and modeling for mathematics instruction was most frequently observed to represent the "Standards for Mathematical Practice." Results indicated that interventions consisting of evidence-based instructional components (e.g., concrete and visual representations; explicit, systematic instruction; range and sequence of examples; heuristic strategies; and use of real-world problems) led to improved performance on measures with fraction concepts and skills. Limitations and directions for future research are discussed.