Psychiatric and substance use disorder (SUD) treatment beds are essential infrastructure for meeting the needs of individuals with behavioral health conditions. However, not all psychiatric and SUD beds are alike: They represent infrastructure within different types of facilities. For psychiatric beds, these vary from acute psychiatric hospitals to community residential facilities. For SUD treatment beds, these vary from facilities offering short-term withdrawal management services to others offering longer duration residential detoxification services. Different settings also serve clients with different needs. For example, some clients have high-acuity, short-term needs; others have longer-term needs and may return for care on multiple occasions. Sacramento County, like other counties throughout the United States, has sought to assess shortages in psychiatric and SUD treatment beds. In this study, the authors estimated psychiatric bed and residential SUD treatment capacity, need, and shortages for adults and children/adolescents at various levels of care: acute, subacute, and community residential services for psychiatric treatment and SUD treatment service categories defined by American Society of Addiction Medicine (ASAM) clinical guidelines. Drawing from various data sets, literature review findings, and facility survey responses, the authors computed the number of beds required-at each level of care-for adults and children/adolescents and identified hard-to-place populations. The authors draw from these findings to offer Sacramento County recommendations to help ensure all its residents, especially Medi-Cal recipients, have access to the behavioral health care that they need.