The purpose of this study was to determine if the implementation of a standards-based grading system has an effect on classroom instruction. In particular, how does the implementation of a standards-based grading system impact the teaching methods, curriculum, differentiation, and formative assessments being used in classrooms? The researcher identified five schools in the Southern Illinois area that have adopted the standards-based grading system and chose eleven teachers to participate in this study through purposeful convenience sampling. This study used a phenomenological qualitative approach. There were two methods used in order to collect data including face to face interviews and document analysis. The findings of this study are significant to any district who is considering changing their grading system from a traditional grading system to a standards-based grading system. Through six major themes that emerged, this study shows that by switching to a standards-based grading system multiple parts of the classroom are impacted including the teaching methods, content, differentiation, and formative assessments. The six major themes included: teaching methods have been modified to better adjust to the standards-based grading system and include a larger variety of approaches, teaching methods are more of a response to student need than a pre-planned approach to teaching, the curriculum and content being taught in the classroom have better alignment to the standards, teachers have a greater awareness of both the curriculum and standards that are being taught at their grade level, as well as at other grade level, teachers have a better understanding of the individual needs of students and have used differentiation to meet these unique needs, and the use of formative assessments have increased in order to adjust for more fluid groupings being used in the classroom.