  Research software is a class of software developed to support research. Today
a wealth of such software is created daily in universities, government, and
commercial research enterprises worldwide. The sustainability of this software
faces particular challenges due, at least in part, to the type of people who
develop it. These Research Software Engineers (RSEs) face challenges in
developing and sustaining software that differ from those faced by the
developers of traditional software. As a result, professional associations have
begun to provide support, advocacy, and resources for RSEs. These benefits are
critical to sustaining RSEs, especially in environments where their
contributions are often undervalued and not rewarded. This paper focuses on how
professional associations, such as the United States Research Software Engineer
Association (US-RSE), can provide this.
