Lapses in care during transition in adult CHD patients lead to increased morbidity and mortality. Previous studies have investigated predictors of poor follow-up in universal healthcare paradigms and select American populations. We studied patients with a wide spectrum of CHD severity within a single American centre to identify factors associated with successful internal transition and maintenance of care. Loss of follow-up was defined as no documented cardiac follow-up for ⩾3 years. Ambulatory cardiology patients aged 16–17 years with CHD were retrospectively enrolled and contacted. A survey assessing demographics, patients’ understanding of their CHD, medical status, and barriers to care was administered. On the basis of chart review of 197 enrolled patients, 74 demonstrated loss of follow-up (37.6%). Of 78 successfully contacted patients, 58 were surveyed, of whom a minority had loss of follow-up (n=16). The status of most patients with loss of follow-up was not known. Maintenance of care was associated with greater complexity of CHD (p<0.01), establishment of care with an adult CHD provider (p<0.001), use of prescription medications (p<0.001), and receipt of education emphasising the importance of long-term cardiac care (p<0.003). Insurance lapses were not associated with loss of follow-up (p=0.08). Transition and maintenance of care was suboptimal even within a single centre. Over one-third of patients did not maintain care. Patients with greater-complexity CHD, need for medications, receipt of transition education, and care provided by adult CHD providers had superior follow-up.