The research question for this study is based on how a PLC of singletons can best affect student scores on reading comprehension by focusing on vocabulary instruction. For the purpose of this research, students who were considered High Risk of not ending the year on grade level were progress monitored biweekly to determine the effect size of two different forms of PLCs on vocabulary instruction. In the first round of PLCs, the teachers implemented the Frayer Model for vocabulary instruction into the first class of the day. The data was compared from before the intervention until the end of the one month intervention. The Dependent Samples T-test found the intervention to be insignificant. In the second round of PLCs, the teachers implemented the Frayer Model in their first class of the day, but also utilized different strategies to work on the same vocabulary words throughout every class of the day. The same Dependent Samples T-test found the second intervention to also be insignificant. Limitations of the study are discussed along with ideas for future investigations.