Decades before the seeds of primary care behavioral health (PCBH) were planted, primary care providers (PCPs) saw the need for better behavioral health services for their patients, and a few were able to bring a mental health provider (MHP) into their clinic. This co-located arrangement was often useful in that it facilitated communication and supported relationship development. However, one big limiting factor was, “you never knew what you were gonna get.” Behavioral health providers have significant differences in their training and professional experiences and differences in their likes and dislikes for providing care. If the job description was essentially to, “do what you like that you know how to do,” their ability to collaborate with PCPs and to serve the large and diverse group of people that PCPs wanted their help with was limited. The PCBH model was developed to do better. It created a new type of MHP, called a behavioral health consultant (BHC). In this chapter, we describe the competencies a BHC needs in order to work effectively, summarized in a tool called the Behavioral Health Core Competency Tool (CCT). An abbreviated version of the CCT is available in Appendix B, and a full-length version (which includes sample behavioral anchors and space to record ratings and comments) is introduced in this chapter and available online at http://behavioralconsultationandprimarycare.com).