AUA is the duly-authorized USA member organization of the International Association of Ultrarunners (IAU).  As such, AUA is responsible for representing American ultrarunners and ultrarunning issues to the IAU. In turn, AUA is responsible for communicating information from and about the IAU and its programs to the American ultrarunning community.

AUA is also a national member organization of USA Track & Field (USATF), the National Governing Body for Track & Field and Long Distance Running (including ultrarunning) in the USA.  AUA has formal voice and voting rights on USATF policies, rules, and decisions affecting the governance and development of ultrarunning in America.  AUA is the only national member organization of USATF which is devoted exclusively to ultrarunning (footracing beyond the standard marathon distance of 26.2 miles).

AUA is committed to promoting the sport of ultrarunning in America through its support of U.S. National Championships, U.S. National Ultra Teams, and ongoing development and promotional programs designed to further the advancement of American ultrarunning.

AUA is run by an Executive Board, comprised of its three elected officers (President, Secretary, Treasurer), plus three other board members appointed by those three.  The day-to-day operations of AUA are handled by an appointed volunteer staff.

Neither AUA nor the IAU are "governing" bodies.  Issues of governance are the province of the International Amateur Athletic Federation (IAAF) and USATF.  The IAU and AUA defer, respectively, to these bodies in matters of governance.  However, the IAAF and USATF rely on the IAU and AUA for information, advice, consultation, and cooperation to serve as their "eyes and ears" in the global ultrarunning community.

AUA works under the principle of minimalist governance and bureaucracy.  AUA's mission is to keep its focus on communication, development, and promotion of the sport, maximizing administrative efficiency.

AUA relies on donations and sponsorships to fund its operations and its programs.