Beginning with an overview of myths around bisexuality and pansexuality, the chapter progresses to provide working definitions of bisexuality and pansexuality as well as research and paradigms that have been used to attempt to frame and study these identities. This chapter explores these orientations and discusses ways in which contemporary concepts of gender intersect with how people may be defining and redefining their sexual orientation. Information about how bisexuality and pansexuality have been marginalized, not just by mainstream heterosexual culture but also by gay and lesbian communities, is provided. This chapter also discusses these as “middle ground” orientations and how they have been explored through research and theory. Implications for social work practice, education, and research are discussed, recognizing that these identities may come with some unique health and social concerns, such as issues of mental health, lack of community, and invisibility. In addition, a call for more targeted research about bisexuality and pansexuality is made. The chapter concludes with some suggestions specific to social workers, providing information on how helping professionals can support people who are bisexual or pansexual.