Individual size distribution (ISD) is the scaling relationship between body mass and density of individuals within a community. Sediment can impact the physical environment where macroinvertebrates live and can carry potentially harmful chemicals and pollutants. Previous studies examine the relationship between the macroinvertebrate communities and chemical properties associated with sediment rather than the physical size of sediment in wadeable streams. This project aimed to explore the relationship between the sediment size of the substrate and the ISD of macroinvertebrates over 21 National Ecological Observation Network (NEON) wadeable streams across North America from Alaska to Puerto Rico. Using a multilevel gamma model, we estimated the particle size distribution of each pebble count survey from 2017 to 2021 and the corresponding ISD of macroinvertebrates. Preliminary results show a more positive relationship between the slopes of finer sediment sites than larger, more cobble sediment sites. Not only is this relationship understudied, but this study provides a potential pathway to using ISD to monitor streams as sediment changes after events of disturbance like flooding.