Adolescents’ routine disclosure and self (non)disclosure to parents have been distinguished conceptually, but rarely empirically. Using latent profile analyses (LPA), these two types of (non)disclosure were operationalized and examined in terms of the patterns of reasons middle adolescents endorsed for not disclosing personal activities and personal feelings to mothers and fathers and their correlates. This was studied in a sample of 489 U.S. Chinese, Mexican, and European heritage middle adolescents (Mage = 16.37, SD = 0.77, 55% females). Three profiles emerged for both mothers and fathers: A majority profile for mothers consisting of adolescents who viewed personal activities and feelings as personal (i.e., private and not harmful), and much smaller sanction-driven and self-conscious profiles. With fathers, personal concerns were separated in the private profile, which also emphasized that fathers would not listen or understand, a harmless profile, and as with mothers, a sanction-driven profile. Overall, but varying in frequency for different profiles, middle adolescents emphasized personal concerns for not disclosing routine personal activities and psychological concerns for self nondisclosure. The profiles also differed by ethnicity/race, generational status, and trust in mothers and fathers. The father private profile and sanction-driven profiles with both parents were associated with more depressive symptoms and problem behavior relative to the other profiles. The results provide insight into why middle adolescents of diverse ethnicities do not disclose personal information to parents.