The campuses include:[9] These campuses share common boundaries with City Montessori schools, but they are totally independent, working separately with affiliations to IGCSE BOARD Cambridge Assessment International Education (CAIE)[10] In 2013, CMS became a centre in Uttar Pradesh for the Scholastic Aptitude Test (popularly known as SAT), the major test used for admission in US universities.

[12] Ramon Magsaysay Award winner Sandeep Pandey staged a hunger strike against CMS and other private school's refusal to admit children of economically weaker backgrounds.

A meeting was arranged between the city administration, Sandeep Pandey, and the school management but neither side was prepared to compromise.

[14][15] The activities of the school have made an impact during testing times, like in 1992, when the Babri Masjid was demolished and religious riots had cost hundreds of lives.

After the student's suicide, upon his parents insistence, the court took cognizance, rejecting the police enquiry and ordered in 2013 that a case should be registered against Sharad.

[25][26] An international music concert was organised at City Montessori School on 20 April with musicians from 17 countries and 11 states of India ABRSM.