Concealable stigmatized identities (CSIs) are identities that can be kept hidden and carry negative stereotypes. To understand the potential influence instructors have as role models, we must first explore the identities instructors have and whether they disclose those identities to undergraduates. We surveyed national samples of science instructors (n = 1248) and undergraduates (n = 2428) at research institutions to assess the extent to which instructors hold CSIs, whether they reveal those identities to undergraduates, how the prevalence of CSIs among instructors compares to their prevalence among undergraduates, and the reasons instructors reveal or conceal their CSIs. The most common CSIs instructors reported were having anxiety (35%) and being a first-generation college student (29%). Relatively few instructors revealed CSIs to students. The largest mismatches of CSI prevalence were for struggling academically in college (-30%) and having anxiety (-25%); all mismatches grew when accounting for instructor CSI disclosure, highlighting that students perceive fewer role models of scientists with CSIs than actually exist.