This report describes the consensus-based selection process undertaken by a voluntary committee of policy/program leaders and epidemiologists from seven states to identify core state indicators to monitor the health of reproductive age women (aged 18-44 years). Domains of preconception health were established based on priority areas within maternal and child health and women's health. Measures (i.e., potential indicators) addressing the domains were identified from population-based, state level data systems. Each indicator was evaluated on five criteria: public health importance, policy/program importance, data availability, data quality, and the complexity of calculating the indicator. Evaluations served as the basis for iterative voting, which was continued until unanimous consent or a super majority to retain or exclude each indicator was achieved. Eleven domains of preconception health were identified: general health status and life satisfaction; social determinants of health; health care; reproductive health and family planning; tobacco, alcohol and substance use; nutrition and physical activity; mental health; emotional and social support; chronic conditions; infections; and genetics/epigenetics. Ninety-six possible indicators were identified from which 45 core indicators were selected. The scope of preconception care and the public health components to address preconception health are still under development. Despite this challenge and other measurement limitations, preconception health and health care indicators are urgently needed. The proposed core indicators are a set of measures that all states can use to evaluate their preconception health efforts. Furthermore, the indicators serve as a basis for improving the surveillance of the health of reproductive age women.