INTRODUCTION: Despite the rising popularity of subcutaneous mastectomy (top surgery) in patients born female and identifying as male or nonbinary, there are limited studies on how prior breast surgeries affect subcutaneous mastectomy. This study evaluates if previous breast reduction affected subcutaneous mastectomy in this patient population. METHODS: The case series consists of 5 patients who, having had prior breast reductions, elected to have subcutaneous mastectomy. The data were collected retrospectively for mastectomy conducted from 2015 to 2016. Demographic data collected included age at surgery, body mass index, smoking status, medical comorbidity, and use of hormone medication. Outcome data included postoperative complications and need for operative revision. Postoperative follow-up was at 1 week and at 1, 3, 6, and 12 months. RESULTS: Patients' ages were between 29 and 46 years with body mass index from 24 to 33 kg/m. They underwent breast reduction approximately 9 to 26 months prior to subcutaneous mastectomy. All 5 patients successfully underwent subcutaneous mastectomy via double incision and free nipple grafts. Blood loss was estimated to be approximately 42 mL. All patients were discharged on the same day of surgery. The last follow-up averaged at 13 months after surgery and no major complication was reported. However, 1 patient required revision of the nipple graft and chest scars. CONCLUSIONS: This small case series suggests that subcutaneous mastectomy could be safely performed in transmasculine or nonbinary patients who had previous breast reduction.