Supercomputing centers exist to drive scientific discovery by supporting researchers in computational science fields. To make users more productive in the complex HPC environment, HPC centers employ user support teams. These teams serve many roles, from setting up accounts, to consulting on math libraries and code optimization, to managing HPC software stacks. Adequately supporting scientists can often be a struggle for the support teams. HPC environments are extremely complex, and combined with the complexity of multi-user installations, exotic hardware, and maintaining research software, supporting HPC users can be extremely demanding. Meeting all of these competing demands of the scientist often results in the creation of new tools and establishment of new policies and best practices. With the third HUST workshop, we will continue to provide a necessary forum for system administrators, user support team members, tool developers, policy makers and end users to discuss support issues. We provide a necessary publication venue to solicit papers on user support experiences, best practices, tools, and innovative efforts to improve user support at supercomputing centers. Learn more at https://hust16.github.io/