The Choctaw Nation Partnership of Summer School Education (POSSE) partners with local school districts within its tribal jurisdiction to provide a 23-day summer learning program for qualifying Kindergarten, 1st, 2nd, and 3rd grade students identified by an approved Oklahoma Reading Sufficiency Act assessment as students in need of intervention. POSSE utilizes a hands-on, engaging educational environment to deliver intense reading and math intervention and enrichment activities. Morning sessions focus on reading and math, and afternoon enrichment activities aim to deliver instruction in STEM, art, music, nutrition, and physical education.

POSSE operates at no cost to families. Each day, students receive a nutritious breakfast, lunch, and an afternoon snack. Students are provided basic school supplies, a camp shirt, and trade books for continued reading practice at home. Also, students attend at least three field trips that align with each bi-weekly educational theme.

POSSE has expanded across the Choctaw Nation to support over 80 school districts in 10 southeastern Oklahoma counties. A total of 3,586 qualifying students in grades Kindergarten through 3rd participated in the 2018 summer session, and 600 Oklahoma teachers and educational support staff were employed to administer the program.