Universal screening and progress monitoring measures are increasingly of interest to early interventionists who make decisions about the services provided to young children. A measure of infant-toddlers' growth in early movement, the "Early Movement Indicator (EMI)," was reported in 2002. However, the EMI has remained an experimental measure based on a small sample and not used broadly by practitioners in real-world programs. We addressed this limitation by advancing knowledge the EMIs scalability through a website and improved psychometrics in a large sample. Results indicated that the EMI was (a) scalable evidenced by a large volume of early childhood staff users in programs in five states with 628 children and 2,258 individual EMI assessments, (b) sensitive to growth over time, (c) comprised of a complex continuum of skill development, and (d) influenced by moderators (i.e., home language, Individual Family Service Plan [IFSP] status). Implications for research and practice are discussed. [This article was published in "Topics in Early Childhood Special Education" (EJ1185519).]