The Department of Defense and partner organizations are developing advanced machine systems that are intended to partner with humans and engage in teamwork to accomplish missions. Given that these human-machine team (HMT) systems have never gone through test and evaluation (T&E), this initial effort looks at the new challenges and provides guidance associated with HMTs. This presentation (1) defines human-machine teaming, (2) describes new challenges in evaluating HMTs, and (3) provides a framework for the categories of metrics that are important for the T&E of HMTs.