The rewards of teaching and learning are reinforced through appropriate assessment of outcomes, short and long term, sequential, and holistic.

Teacher Assessment – Students are assessed on a trimester schedule, using a social development, work habits and skills checklist, as well as a written narrative in all subject areas. Sixth, seventh and eighth grade pupils also receive number grades in math, reading, writing, and theme studies. Weekly updates summarize short-term performance related to responsibility, behavior, and classroom attitude. Checklists and teacher narratives give a full picture of progress during the school year.

Student Self-Assessment – Students that excel learn to measure their own success. Rubrics are used as a mechanism to guide student projects. At GMS, we believe that students do their best work when there are clear guidelines for finished projects.

Due in part to its small size, GMS students are well prepared for a variety of learning environments. Many GMS graduates attend Baltimore's magnet high schools—The Baltimore School for the Arts, Baltimore City College, Western Senior High, and Ingenuity at Polytechnic Institute. Other graduates go on to local private high schools such as Park School, Notre Dame Preparatory, Calvert Hall, as well as a number of well-respected parochial schools in the area.