In the weeks prior to menstruation, many individuals experience mood and physical symptoms that negatively impact their quality of life and functioning. Approximately 5% of women and menstruating individuals have such severe symptoms that they meet criteria for Premenstrual Dysphoric Disorder (PMDD). Further, of those with underlying mood disorders (i.e., depression, bipolar disorder) about 60% have cyclical worsening of symptoms classified as premenstrual exacerbation (PME). Both PMDD and PME are associated with significant impairment, yet limited effective options exist to treat these conditions. In this project, the investigators will adapt and evaluate an Acceptance and Commitment Therapy (ACT) group for PMDD and PME, entitled ACT-Premenstrual (ACT-PM), delivered virtually to maximize accessibility. The investigators will examine whether ACT-PM is feasible to deliver and whether it is acceptable to group participants and those facilitating the group. The study will lay the groundwork for future research to determine if the group is effective. If effective, the intervention could be scaled up to improve quality of life and outcomes for individuals suffering from PMDD and PME.