Manned Unmanned Teaming (MUMT) is fast becoming a critical capability for maintaining operational superiority and overmatch against near peer competitors. However, there is presently no concept of MUMT behaviors in Model Based Systems Engineering (MBSE) analyses. Such a concept is needed in order to capture and understand the increasingly complex interactions between humans and machines that will govern system behavior on the battlefield. This manuscript describes an effort that sought to identify and roadmap the development of the MUMT requirements necessary to build into the next generation of functional MBSE models that lead to sustainable autonomous (semi or full with MUMT) military operations. Three scenarios spanning the unmanned systems domain incorporating current state of practice and envisioning increased autonomy were used as the basis for developing a generalizable MBSE expression of MUMT behavior.