The integrated comprehensive school (IGS) teaches pupils in grades 5 to 13. The IGS can also be run without a grammar school upper level (school years 11 to 13). The IGS in Lower Saxony is generally run as an all-day school

The IGS leads to the following qualifications at the end of lower secondary level:

• Hauptschulabschluss after year 9
• Secondary school leaving certificate I - Hauptschulabschluss
• Secondary school leaving certificate I - Realschulabschluss
• Extended secondary school leaving certificate I

Obtaining the Extended Secondary Certificate I entitles the student to enter the introductory phase of the upper secondary school (11th grade). At the end of the qualification phase after 13 school years, the general higher education entrance qualification is acquired through the Abitur examination.

The gymnasiale Oberstufe is divided into a one-year introductory phase (year 11) and a two-year qualification phase (years 12 and 13), ending with the Abitur examination after 13 school years.

Successful completion of the Abitur examination leads to a general higher education entrance qualification. This entitles the student to take up any course of study at a university, college or university of applied sciences, irrespective of any university admission procedures and admission requirements.

The principle of integration that characterizes the IGS is reflected in the fact that all pupils are taught according to a common curriculum and participate together in lessons in the various subjects and in school life as a whole. However, the IGS is also a differentiating type of school. External subject performance differentiation through subject performance courses is carried out at various levels in the subjects of mathematics and English from the 7th school year, in German from the 8th school year and in science from the 9th school year at the latest.

In the cooperative comprehensive school (KGS), the school types Hauptschule, Realschule and Gymnasium are brought together "under one roof" as interrelated and interconnected school branches. The school can also be divided into school years. Pupils in years 5 to 13 are taught at the KGS; however, the school can also be run without years 11 to 13 (upper secondary school).

The same qualifications can be obtained at the KGS as at the IGS (see above). The respective regulations of the corresponding school types apply to the course of education and graduation requirements.

Lessons at the KGS are taught for specific school branches and across school branches. According to the decision of the school board, lessons in grades 5 to 8 can be taught predominantly in inter-branch learning groups. The core curricula of the respective school form apply to subject teaching in KGS lessons specific to a school branch, while the core curricula of the IGS apply to subject teaching in cross-branch learning groups.