Each spring, Decatur Heritage begins the enrollment period with the re-registration of existing students. Siblings of current students are also eligible to enroll during this time. At the conclusion of re-registration, open enrollment begins for new students (normally the last week of March). The enrollment process continues until each class reaches capacity, after which point a waiting pool is established. As openings come available, students will be selected based on best fit for the school, not necessarily on the order in which they entered the pool.

Selection of students for admission is based upon achievement as demonstrated by a standardized testing program and classroom grades, school conduct reports, the spiritual background of the family, an interview with the site principal, and the completion of the registration/enrollment process.The school will not admit students following suspension, expulsion or dismissal from another school, public or private. Decatur Heritage Christian Academy does not discriminate on the basis of race, color, or national or ethnic origin in the administration of its admission policies or financial aid process.

Upon admission, the academic and social adjustment of new students will be closely monitored during the first nine weeks and recommendations will be made at the first parent conference at the end of the quarter. All students are admitted on a probationary basis the first semester.