Background: The approach to vascular access in children with CHD is a complex decision-making process that may have long-term implications. To date, evidence-based recommendations have not been established to inform this process. Methods: The RAND/UCLA Appropriateness Method was used to develop miniMAGIC, including sequential phases: definition of scope and key terms; information synthesis and literature review; expert multidisciplinary panel selection and engagement; case scenario development; and appropriateness ratings by expert panel via two rounds. Specific recommendations were made for children with CHD. Results: Recommendations were established for the appropriateness of the selection, characteristics, and insertion technique of intravenous catheters in children with CHD with both univentricular and biventricular physiology. Conclusion: miniMAGIC-CHD provides evidence-based criteria for intravenous catheter selection for children with CHD.