All members of the International Mathematical Union (IMU), are automatically members of ICMI. But it is also possible for a country not a member of IMU to become a member of ICMI. (Information on this matter can be obtained here or from the Secretary-General of ICMI.)
There are currently 93 member countries of ICMI, 73 of which are also members of IMU and 8 are associate members (am) of IMU. In the following list, (*) indicates one of the 12 members of ICMI that are not members of IMU.
Each member country of ICMI shall appoint a representative to ICMI.
This appointment is the responsibility of the IMU Adhering Organization, for those countries which are Full or Associate Members of IMU, and of the ICMI Adhering Organization, for the other countries co-opted under item (8) in the ICMI Terms of reference.
A representative should normally not serve for more than two consecutive four-year terms.