This study informs the U.S. Departments of Labor and Education about options to consider for the adoption of one or more effectiveness in serving employers measures (ESE measures) across all Workforce Innovation and Opportunity Act (WIOA) core programs. The ultimate goal for supporting successful implementation of the ESE measures is to improve the effectiveness of services to employers, a primary customer of the public workforce system, and develop a skilled workforce to compete in the global economy. Since Program Year 2016, states have reported annually on at least two of three pilot measures. The three measures piloted were Retention with the Same Employer, Employer Penetration Rate, and Repeat Business Customers. The study found that states put in place systems for measuring employer services and aligning data collection with requirements for the pilot. Although the pilot measures and definitions had some limitations, they were useful for improving data collection related to services provided to employers. States largely did not develop or identify alternative measures for assessing those services, which was an option. For each ESE measure piloted, the study team identified challenges to validity, reliability, practicality and unintended consequences of the measures, as well as strengths and other limitations. The analysis reveals various options and factors for the Departments of Labor and Education to consider when selecting one or more final measures in the future. The authors raise several options for next steps, including further research on the implementation of the ESE measures, additional examination of alternative measures and data, and the development of statistical adjustment models. Future research can also support continued implementation of adopted ESE measures in WIOA programs and by other public agency and private entity stakeholders that provide services to employers.