Prenatal substance exposure is a significant public health problem affecting 10% of infants (over 360,000 in 2020). Criminal justice-oriented policies enacted to protect these newborns are associated with negative consequences for both the mother and infant, suchas lower rates of maternal substanceuse treatment utilization in pregnancy, higher rates of neonatal opioid withdrawal syndrome (NOWS) diagnoses at birth, and disproportionately higher child protective services (CPS) referral rates for Black and Indigenous infants. On the other hand, states without substance-exposed infant policy lack infrastructure for systematic responses to support these families. In 2016, the primary U.S. child welfare policy—the Child Abuse Prevention and Treatment Act (CAPTA)—was amended to increase mother-infant health and substance use treatment utilization while ensuring infant safety by mandating that all dyads receive a plan of safe care. Seeking to protect dyads from intensive surveillance and threat of foster care placement, in 2019 Connecticut became the only state to use a “masked” approach that requires plans be developed by community providers with perinatal mothers without disclosing their identifiable information to CPS. Dr. Margaret Lloyd Sieger is one of a small handful of researchers in the U.S. working to identify how public health policy can increase health and safety for substance exposed infant-mother dyads. Her preliminary research in Connecticut indicates that providers are developing plans with mothers. With this K01 award and support from three state agencies, two large birthing hospitals, and a multidisciplinary mentorship team of national experts, Dr. Lloyd Sieger will apply a theory of health services utilization to examine the effect of plans of safe care on: (1) substance use treatment utilization, (2) child safety, and (3) racial disparities in CPS involvement. The proposed project will achieve its aims using innovative, scientifically rigorous approaches to linking three state administrative databases and recruiting mothers at the time they develop a plan of safe care for a longitudinal survey. This K01 award will provide Dr. Lloyd Sieger with training and experience in: (1) pertinent, multisystem clinical issues, (2) longitudinal survey research with perinatal mothers, (3) statistical methods for multi-system data linkage and multilevel analysis, and (4) collaborations for multi-site, multi-state research. This award will also lead to an R01 proposal to conduct a multi-site, multi-state study on plans of safe care, thereby addressing NIDA’s priorities to understand effective policies that prevent child welfare system involvement for mothers with substance use disorders and infants with prenatal substance exposure. Finally, this award will set the foundation for Dr. Lloyd Sieger’s productive, independent program of research that integrates substance use epidemiology, policy, and clinical interventions to improve outcomes for pregnant ...