Through a narrative study of three second-career teachers who started their professional lives as English-as-a-second-language (ESL) teachers and then became Chinese-as-a-second-language (CSL) teachers, we examine how the participants constructed their professional identities across their trans-professional experiences. In this study, we define trans-professional experience as the occupational change when one switches from teaching one subject area to another. This study details how the participants experienced the career transitions from teaching English to Chinese and how their trans-professional experience contributed to their professional growth. Findings from narrative interviews with the participants reveal that the teachers' second-career identities were constructed through brokering, which involved meaning negotiation when they moved across boundaries of schools, subject areas, and pedagogical systems. This study sheds light on a broader context of career transition and trans-professional practice among second language teachers.