Background Although the number of hospital visits has exponentially increased for adults with congenital heart disease (CHD) over the past few decades, the relationship between insurance status and hospital encounter type remains unknown. The purpose of this study was to evaluate the association between insurance status and emergent versus nonemergent encounters among adults with CHD ≥18 years old. Methods and Results We used California Office of Statewide Health Planning and Development Database from January 2005 to December 2015 to determine the trends of insurance status and encounters and the association of insurance status on encounter type among adults with CHD. A total 58 359 nonpregnancy encounters were identified in 6077 patients with CHD. From 2005 to 2015, the number of uninsured encounters decreased by 38%, whereas government insured encounters increased by 124% and private by 79%. Overall, there was a significantly higher proportion of emergent than nonemergent encounters associated with uninsured status (13.0% versus 1.8%; P<0.0001), whereas the proportion of nonemergent encounters associated with private insurance was higher than emergent encounters (35.8% versus 62.4%; P<0.0001). When individual patients with CHD became uninsured, they were ≈5 times more likely to experience an emergent encounter (P<0.0001); upon changing from uninsured to insured, they were significantly less likely to have an emergent encounter (P<0.001). After multivariate adjustment, uninsured status exhibited the highest odds of an emergent rather than nonemergent encounter compared with all other covariates (adjusted odds ratio, 9.20; 95% CI, 7.83-10.8; P<0.0001). Conclusions Efforts to enhance the ability to obtain and maintain insurance throughout the lifetime of patients with CHD might result in meaningful reductions in emergent encounters and a more efficient use of resources.