Southminster School is fully accredited by the Southern Association of Colleges and Schools Council on Accreditation and School Improvement (SACS CASI). SACS CASI is a nationally and internationally recognized accrediting agency. Additionally, SACS  CASI is recognized by the Texas Education Agency (TEA) as an accrediting institution of high standards. Southminster School received accreditation from SACS CASI during the first year of eligibility. Following a review of the completed self-study report developed by the Accreditation Team, and observations in both the elementary and preschool, Southminster School was awarded full accreditation. Southminster School believes the ongoing self-evaluation and reporting that is required to maintain accreditation status serves to ensure that all elements within the school are regularly assessed and improved to continually meet the highest educational standards.

Southminster School renewed its membership with the Association of Christian Schools International (ACSI) and with the National Association for the Education of Young Children (NAEYC). These memberships allow the teachers and the school to receive updates to standards for preschool and elementary education, participate in special workshops, and receive research information pertaining to items like teacher retention, child development, and marketing to name a few.

Southminster School is considered a school in good standing and is recognized as a member school by the ACSI and NAEYC boards.

Southminster School is accredited by:
Southern Association of Colleges and Schools Council on Accreditation and School Improvement and the Commission on International and Trans-Regional Accreditation

Memberships include:
Association of Christian Schools International
National Association for the Education of Young Children
Houston Area Association for the Education of Young Children
Houston Association of Independent Schools