This action research was driven by the researcher's interest in mixed ability guided reading groups and the effect they can have on student fluency scores and reading assessments. The researcher utilized mixed ability guided reading groups for nine weeks, while monitoring progress using FastBridge CBMreading fluency passages weekly. The research was conducted to analyze the effectiveness of mixed ability grouping within guided reading groups. The researcher is a second grade teacher in her ninth year of teaching. The findings revealed a common trend of increased fluency and accuracy within words per minute, specifically for students who fell below benchmark when the study began. This research was conducted to impact future classroom practices as well as school wide decisions in practices pertaining to guided reading interventions.