Teachers and administrators expressed concerns regarding grading English Learner (EL) students in a school district in a mid Atlantic state. Grade retention rates of ELs were disproportionately high. A professional development pilot was designed and implemented based upon the district's recently developed EL Grading Guidelines. The purpose of this qualitative case study was to determine the effectiveness of the professional development and to determine how the professional development could become operational in the district. Pilot meetings, observations, documentation, and interviews were described in this case study. Participants submitted assessments adapted for ELs during the pilot and administered those adapted assessments. Results indicated that teachers gained self-efficacy in equitably assessing and grading ELs on rigorous content assessments. Participants emphasized the importance of collaboration, application of assessment adaptation techniques, and examples from colleagues in the professional development. They emphasized the importance of the professional development in the pilot and noted reasons for their buy in such as its usefulness. Expansion of the professional development is recommended. Further research is needed on how to equitably grade and assess newcomer including Students with Interrupted Formal Education (SIFE). Recommendations include developing a team problem solving approach to determine solutions for this concern. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]