The Identity Process Treatment Model for transgender and gender-nonconforming clients addresses an important development in the identity development models. Specifically, this theory and treatment model provide an alternative or adjunct to existing stage theories. Unique to this model is the ability to understand how the client's identity is impacted by their day-to-day experiences. We propose that clients adopt an identity style that they rely upon in most situations. In this model we discuss three different identity styles and the style that is expected to be the most adaptable and to promote psychological health across time. A six-step treatment model is provided to guide clinicians providing service to transgender and gender-nonconforming clients. These steps include an assessment period, conceptualizing the client's identity style, providing psychoeducation to both the client and support system, working toward a more balanced identity style, and consolidating the learning.