Three more Atlanta schools are now certified for their focus on STEM subjects.

Atlanta Public Schools announced in late March that Heritage Academy Elementary School, Humphries Elementary School and South Atlanta High School were granted the certification from Cognia, a nonprofit educational accrediting organization.

The cluster of elementary and middle schools that feed into South Atlanta High School have a focus on science, technology, engineering and math as part of their signature programming.

Other Atlanta schools to receive the approval in recent months include Usher-Collier Elementary School, Booker T. Washington High School, Tuskegee Airmen Global Academy and Dobbs Elementary School.

The certification process includes interviews with students, teachers and parents as well as other reviews by Cognia officials.