Previous research demonstrates that early childhood experiences play a role in later mental and physical health outcomes. However, we know far less about adult adoptees. This study investigates relationships between adoption type (international adoption to the U.S., U.S. private domestic adoption, or adoption from U.S. foster care) and physical health and mental well-being of adult adoptees. Utilizing data from the Mapping the Life Course of Adoption Project, we examine associations between adoption type and physical and mental health outcomes, accounting for participants’ gender and current age. The Brief Symptom Inventory (BSI) assesses mental health symptoms, and the Patient-Reported Outcomes Measurement Information System (PROMIS) assesses global physical health and number of chronic diseases. A series of one-way ANOVAs will be conducted with adoption type predicting the three health outcomes. Independent samples t-tests will probe which groups show differences. A multivariate general linear model will examine health outcomes with adoption type, gender, and current age as predictors. Finally, partial correlations will be run between health outcomes, controlling for gender and current age, to examine relations between physical and mental health in each adoption group. Identifying possible associations between adoption type and long-term physical and mental health can be useful in increasing resources for adult adoptees. Such research can provide guidelines for mitigating health risks or increasing awareness of adoptee mental health and well-being. Future research should continue to explore potential predictors of long-term health for adult adoptees.