Male-partnered sexual minority women (SMW) have received little research attention, although they represent a large proportion of SMW, particularly child-bearing SMW. Male-partnered SMW are less “out” than female-partnered SMW and will likely be “read” as heterosexual by perinatal providers. Given this, and evidence that pregnant women have unique mental health care needs, the current study focuses on male-partnered SMW (n = 28) during the perinatal period, recruited from Toronto, Canada and Massachusetts, United States, in an effort to understand disclosure and concealment processes in general and specifically to perinatal health-care providers. Women generally reported that they did not disclose (but made no effort to conceal) their sexual identities and histories in new or unfamiliar relationships, largely because the topic rarely came up, although some women highlighted bisexual invisibility and fear of biphobia as reasons for nondisclosure. Despite overall positive experiences with perinatal providers, less than one quarter of the sample (n = 6) had disclosed their sexual identities and histories to them. Most women felt that this information was generally not relevant to their health care, and particularly their reproductive/obstetric care, although some believed that disclosure would be appropriate under conditions of sexual health risk (n = 8). Others noted that although they did not feel the need to disclose, they did prefer an lesbian, gay, bisexual, and queer (LGBQ)-affirming provider (n = 7). Findings provide insight into male-partnered SMW’s views and patterns of disclosure during the perinatal period and have implications for providers, organizations, and scholars who interface with SMW.