Despite the growth of biomedical and feminist research on menopause, we still lack a comprehensive definition of what reproductive aging is, when it begins, how long it lasts, and how women experience different menopausal stages. Likewise, while aging scholars have made strides in understanding age identities and the meanings attributable to various chronological ages, we lack an understanding of how chronological age figures into individuals' experiences, medical treatment, and academic research. The gaps in knowledge about chronological age are particularly glaring in regard to women's experiences. In this article I use data from 61 in-depth interviews with menopausal women to explore the ways in which chronological age appears in their discussions of menopause experiences and their interactions with doctors about this reproductive transition. I also describe how chronological age shaped recruitment efforts for my own study. I conclude that, despite unclear information about the age and time boundaries of reproductive aging, we still use chronological age as a way to diagnose and operationalize women's experiences at midlife. I argue that reliance on chronological age hinders understandings of menopause, women's midlife, and women's overall well being. Even though feminist research exists on the topics of menopause and aging already, feminist scholars need to work toward broader conceptualizations of menopause, women's midlife experiences, and aging processes and challenge existing definitions of menopause more directly.