Criteria for defining CHD centers of expertise (must have ≥1 criterion).

*International Society for Adult Congenital Heart Disease (ISACHD) fellowship directory. http://isachd.org/fellowship. Accessed December 16, 2013. ACHD = adult congenital heart disease.†American Council of Graduate Medical Education program listing. https://www.acgme.org/ads/Public/Programs/Search. Accessed December 16, 2013.‡Practices registered as ACHD practices in the Adult Congenital Heart Association (ACHA)/ISACHD database. http://www.achaheart.org/home/clinic-directory.aspx. Accessed December 16, 2013.§Congenital Heart Surgeons Society member directory. http://chss.org/multimedia/files/Member-Directory.pdf. Accessed December 16, 2013.Criteria for defining CHD centers of expertise (must have ≥1 criterion).