The interstellar medium is the vast bulk of the volume of a galaxy. It provides the raw material for star formation and in turn absorbs much of the energy produced by the newly formed stars. It acts as a repository for mass ejected during the last phases of stellar evolution by AGB stars and SNe, and as such forms the main step in the chemical enrichment evolution of a galaxy. Dust and molecules in the interstellar medium act as a major sink for refractory and volatile elements such as carbon and iron. The circumstellar and interstellar material are closely related in this cycle of evolution. ALMA, JWST and SKA will open up important new avenues in this area of research, through dust emission and atomic and molecular gas. The goal of this session is to bring together and stimulate interaction between groups working on the Galactic interstellar medium, extragalactic ISM, and circumstellar ejecta.