<p>Numerical propagation techniques have been extensively studied and are routine for precise satellite operations. Most studies focus on time spans of a few days to several weeks, specific orbital classes, or interplanetary orbits. As long-term numerical operations become more commonplace, it is useful to quantify accuracy performance for propagations of several months, to years. This paper performs long-term numerical propagation comparisons against reference orbits in a variety of orbital classes. Semianalytical techniques are also used in the comparisons including a general discussion of the initial osculating to mean element conversion. Finally, orbital size, shape, and orientation considerations are examined.</p>