Access to high-quality resources is integral for educators to provide research-aligned mathematics instruction. Identifying the supplemental resources educators use to plan mathematics instruction can inform the ways researchers and organizations disseminate research-based practices. The goal of this study was to identify the frequency in which early childhood educators (i.e., pre-Kindergarten through third grade) reported using various resources to plan for mathematics instruction. Furthermore, we investigated whether differences were observed based on teacher factors (i.e., general or special education, route to certification, years of experience) and locale (i.e., rural, urban, suburban). We retained data from 917 teachers for data analysis. The three most frequently reported resources by educators were colleagues, Teachers Pay Teachers, and Google/Yahoo. The three least frequently reported resources were the typical outlets researchers use to reach teachers: What Works Clearinghouse, Teaching Exceptional Children, and Teaching Children Mathematics. General and special education teachers differed on their self-reported usage of five resources: colleagues, Google/Yahoo, teaching blogs, Teaching Exceptional Children, and the What Works Clearinghouse. Rural educators self-reported that they were less likely than suburban educators to use colleagues or specialists at the district to plan instruction. Implications for future research and practice are discussed.