BackgroundThe transvenous implantable cardioverter‐defibrillator (ICD) lead is the most common source of complications in a traditional ICD system. This investigation aims to determine the incidence, predictors, and costs associated with these complications using a large insurance database.Methods and ResultsData from the OptumLabs™ Data Warehouse, which include diagnosis, physician and procedure codes, and claims from patient hospitalizations, were analyzed. Patients with a de novo ICD or cardiac resynchronization therapy defibrillator implanted from January 1, 2003, through June 30, 2015, were included; those who did not have continuous coverage beginning 1 year before implantation were excluded, resulting in 40 837 patients followed up over an average of 2.3±2.1 years. Patients were followed up until they had the procedure or their last active date in the database. Of 20 580 device procedures, 2165 (5.3%) and 771 (1.9%) had mechanical and infectious complications, respectively. The 5‐year rate of freedom from mechanical complication was 92.0% and 89.3% for ICDs and cardiac resynchronization therapy defibrillators, respectively. Infectious complications were more likely in patients with a history of atrial fibrillation, diabetes mellitus, and renal disease, and the risk increased with subsequent device procedures. Younger age, female sex, lack of comorbidities, and implantations between 2003 and 2008 were associated with more mechanical complications.ConclusionsIncidence of mechanical and infectious complications of transvenous ICD leads over long‐term follow‐up is much higher in the real world than in clinical studies. In our study cohort, 1 of 4 transvenous ICD leads had mechanical complications when followed up to 10 years. The high rate of reintervention leads to additional complications.