The Department of Health and Human Services, through the NIH, is issuing a funding opportunity for accessing limited identifiable data or biospecimens from the Environmental Influences on Child Health Outcomes (ECHO) Cohort. The purpose of this program is to enable researchers to study critical areas of maternal and child health, primarily through ancillary studies funded by non-ECHO sources. Applicants must secure X01 awards, which do not provide funding but ensure adherence to NIH policies while utilizing the ECHO resources. The opportunity is open to a diverse array of institutions and individuals across the scientific community. Research proposals may focus on areas such as early developmental exposures and their impact on child health, with an emphasis on innovative approaches. Key requirements include a Letter of Support from the ECHO Cohort Steering Committee and documented non-ECHO funding to cover all research expenses. The application process is detailed, involving specific guidelines for submission and compliance, including maintaining participant privacy and securing data integrity. The review process will evaluate applications for scientific merit, investigator qualifications, and the significance of the research. This initiative is integral to advancing understanding of how environmental factors influence childhood health, supporting a comprehensive approach to child health research nationwide.