ISI has received support in the form of grants, training and consultation from the Office of Overseas Schools in Washington, D.C. since the 1960s.

This allows students to attend ISI for their entire grunnskoli career before moving directly to menntaskóli (secondary) education.

The Bilingual stream is intended for students who live in Iceland on a permanent basis or for an undetermined length of time.

[5] In May 2023, ISI was the second school after Menntaskólinn við Hamrahlíð to offer any form of International Baccalaureate education in Iceland with the introduction of the IB Middle Years Program for grades 7-10.

In 2017, ISI received joint accreditation with both CIS and MSA (Middle States Association of Colleges and Schools) organizations.

In May 2014, the school hosted a celebration of its 10-year anniversary; guests included the Minister of Education, the mayor of Garðabær, representatives from local embassies, and former and current students.

[9] In the spring of each year, students in grades 5-6 raise money to go on an overnight trip in the Icelandic countryside.