IAML has national representation in 25 of its 57 member countries: Australia, Austria, Belgium, Canada, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Germany, Hungary, Italy, Japan, Netherlands, New Zealand, Norway, Poland, Russia, Slovakia, Spain, Sweden, Switzerland, the United Kingdom & Ireland and the United States. The IAML branch usually serves as the national music library organization in its country.
In countries that lack a strong music library/archive tradition, the establishment of a national branch of IAML has often been the first step towards activities and improved standards at the national level.