Child care and early education (CCEE) educators typically have low levels of compensation; limited opportunities for education, training, and professional development; inconsistent working conditions; and high levels of stress and burnout. There are also high rates of job turnover, which can strain remaining educators and decrease the quality of care they offer. Policymakers at the federal and state levels are taking steps to build and stabilize the CCEE workforce, but effectively addressing these challenges requires a better understanding of the issues. The Building and Sustaining the Child Care and Early Education Workforce (BASE) project aims to increase knowledge and understanding about the CCEE workforce by documenting factors that drive turnover and by building evidence on current initiatives to recruit, advance, and retain a stable and qualified CCEE workforce. Wage data from state Unemployment Insurance (UI) systems can be used to address some of the most pressing policy and research questions about the CCEE workforce because they track individual-level employment and quarterly earnings over time and across employers. This brief describes how these data can support longitudinal analyses that address the following questions: (1) How do educators enter and exit the CCEE workforce over time? (2) Which other industries do educators work in before and after child care employment? (3) When and how often do educators change CCEE employers or leave the industry? (4) How do wages change over time for CCEE work? and (5) How do CCEE wages compare with wages in other industries? A better understanding of how CCEE workers move through the labor market can inform the development of targeted recruitment and retention strategies, as well as evaluations of these strategies. This brief is a technical primer for researchers or agencies interested in using UI wage data to better understand the labor market experiences and, especially, the job trajectories of CCEE workers. Informed by a series of analyses of Illinois UI wage data, this brief describes how child care workers can be identified and characterized in these data, and suggests methods to measure important aspects of their employment, such as job duration, wages, and retention. This brief also includes a short discussion of possibilities for linking UI wage data to other data sources to address these limitations.