<p>Determining when calls to the police involve mental health issues is important for the effective response by police and the potential diversion of such calls away from the police. However, making such determinations can be challenging due to the nature of emergency calls and the constraints imposed by the call handling process. As part of this study, we sought to explore how police dispatchers classify calls for service in the context of mental health. Using real call data from two 911 call centers within the Roanoke Valley of Virginia, we assessed the overlap, or lack thereof, among classifications of the <i>same</i> calls for service (<i>N</i> = 1,161) by police dispatchers, police officers, and mental health clinicians. Our analyses revealed heterogeneity in classifications: with dispatchers classifying fewer numbers of calls for service, and clinicians classifying greater numbers of calls for service, as mental health-related when compared to the classifications of on-scene officers who attended such calls. We discuss our results in the context of the call handling process and the implications of call classification for various outcomes.</p>