BackgroundLifelong continuity of care is imperative for patients with congenital heart disease (CHD); unfortunately, gaps in care (GIC) are common.MethodsAll patients aged 0-34 years followed at a pediatric subspecialty hospital (primary location Delaware; satellites covering Pennsylvania, New Jersey, Maryland) with CHD who underwent surgery between January 2003 and May 2020 were included. Patients were categorized as simple, moderate, and complex CHD based on 2018 American Heart Association and American College of Cardiology guidelines. Social determinants of health factors such as age, race, ethnicity, sex, language, insurance status, and Child Opportunity Index based on home address zip code were analyzed.ResultsOf 2012 CHD patients, a GIC of ≥3 years was identified in 56% (n=1119). The proportion of patients with GIC per year increased for all patients. Multivariable longitudinal models with all CHD patients showed that GIC are increasing for patients who are ≥10.5 years old, have simple CHD, live out of state, live farther from a site of care (hospital or satellite clinics), receive public insurance and/or have less protection with additional insurance plans, and reside in low Child Opportunity Index neighborhoods. A separate model for only moderate/complex CHD patients showed similar findings. Neither longitudinal model showed race/ethnicity as significant for increasing GIC trends.ConclusionsGIC have continued to increase with an aging CHD population with social determinants of health factors specifically related to insurance, access, and neighborhood opportunity. Attenuating GIC necessitates standardized practices while simultaneously addressing the impact of SDOH on all CHD patients.Clinical PerspectiveWhat is new?This study is the first to examine gaps in care (GIC) trends over time in patients with repaired congenital heart disease (CHD) and found that almost half had GIC.Over 2 decades, GIC are increasing for certain subpopulations of CHD patients based on social determinants of health, including being older, lacking insurance, and residing in low Child Opportunity Index neighborhoods.What Are the Clinical Implications?GIC are worsening in certain subpopulations of CHD patients, including those with low Child Opportunity Index, lack of insurance, or poor access to health care systems.CHD programs must target social determinants of health factors to improve ongoing care and long-term outcomes for all patients.