OBJECTIVE: The Stages of Reproductive Aging Workshop +10 (STRAW +10) criteria are the gold standard criteria for categorizing menopause stage, with stage typically categorized using three menopause stages. Although STRAW +10 criteria include additional substages, few studies have examined menopause symptoms by these substages. To better characterize menopause stage effects on sleep, this study examined sleep quality across three stages and six substages of menopause. To differentiate menopause effects from aging effects, the study further examined associations between age and sleep quality. METHOD: Participants included 239 women aged 40-60 years from the Human Connectome Project in Aging (HCP-A) and the Aging Adult Brain Connectome (AABC). Sleep was measured using the Pittsburgh Sleep Quality Index and menopause was staged according to STRAW +10 criteria using three stages and six substages. All analyses were conducted using mixed-effects models. RESULTS: Independent of age, sleep quality declined linearly across six substages of menopause, but not three stages of menopause. Age was unrelated to sleep quality after adjustment for menopause stage. CONCLUSION: Midlife represents a window of vulnerability to incrementally worse sleep associated with reproductive, but not chronological, aging. Findings highlight the benefit of using STRAW +10 substaging in menopause research.