Although jobs in science, technology, engineering, and math (STEM) fields are projected to grow at twice the rate of other professions, too many students, especially women and minoritized students, choose not to study or drop out of STEM fields, in part because they do not identify with STEM. With Communication Theory of Identity as a sensitizing framework, this study focused on a group of students who are "at risk" for dropping out of STEM due to unmet financial need who are participating in a scholarship program designed both to close their financial need gap and to build their STEM identities. Based on Interpretive Phenomenological Analysis of 20 semi-structured interviews, the findings show that these students largely, but not exclusively, saw being a "STEM person" as positive, but also expressed varying degrees of certainty and potential "identity gaps" about their STEM identities. Enacted and relational STEM identities were of particular importance to how these students understood and experienced STEM identity. Women and minoritized students spoke of the importance of seeing and interacting with STEM people who share their social identities in developing their own STEM identities. Implications for a communication theory of STEM identities are discussed.