National data suggest the rate of youth homelessness has been increasing over the last several years. However, estimates of the true prevalence of youth homelessness vary greatly based on counting method and definitions of homelessness. The purpose of the present study is to demonstrate how the Youth Risk Behavior Survey (YRBS) could be used to understand the prevalence of youth homelessness, characteristics of homeless experiences, and how these experiences relate to mental health problems among youth. Findings demonstrate the number of youth identified as homeless by the YRBS are considerably higher than the number identified by traditional counting methods. Furthermore, youth experiencing homelessness reported disproportionately higher rates of mental health problems than their housed peers. Implications for practice, policy and future research are discussed.