Health professional education is rooted in patient interaction. The utilization of the simulated participant method is a widely accepted approach in this regard, as it enables students to engage in experiences that closely resemble real patient interactions. So, the simulated participants need to be well-prepared and well-engaged in the concept of their roles. The purpose of the study is to evaluate a new model for identity formation of simulated participants based on communities of practice theory. An 8-month follow-up study with pre- and post-interviews, observations, and reflective diaries designed with a qualitative approach. The results were categorized together under the five themes: "motivation of simulated participants", "background of simulated participants", "interaction between simulated participants as a part of a community of practice", "limitations from simulated participants' perspectives", and "roles of simulated participants in simulation". Our model based on communities of practice theory is an effective method for the formation of identities of simulated participants. Educators have the responsibility to improve the quality of simulated participant-based simulation. Our model can be thought of as an effective tool to use in this regard.