The Centers for Medicare & Medicaid Services added lung cancer screening with low-dose computed tomography (LDCT) as a Medicare preventive service benefit in 2015 following findings from the National Lung Screening Trial (NLST) that showed a 16% reduction in lung cancer mortality associated with LDCT. A challenge in developing and promoting a national lung cancer screening program is the high false-positive rate of LDCT because abnormal findings from thoracic imaging often trigger subsequent invasive diagnostic procedures and could lead to postprocedural complications. To determine the complication rates and downstream medical costs associated with invasive diagnostic procedures performed for identification of lung abnormalities in the community setting. A retrospective cohort study of non-protocol-driven community practices captured in MarketScan Commercial Claims & Encounters and Medicare supplemental databases was conducted. A nationally representative sample of 344 510 patients aged 55 to 77 years who underwent invasive diagnostic procedures between 2008 and 2013 was included. One-year complication rates were calculated for 4 groups of invasive diagnostic procedures. The complication rates and costs were further stratified by age group. Of the 344 510 individuals aged 55 to 77 years included in the study, 174 702 comprised the study group (109 363 62.6% women) and 169 808 served as the control group (106 007 62.4% women). The estimated complication rate was 22.2% (95% CI, 21.7%-22.7%) for individuals in the young age group and 23.8% (95% CI, 23.0%-24.6%) for those in the Medicare group; the rates were approximately twice as high as those reported in the NLST (9.8% and 8.5%, respectively). The mean incremental complication costs were $6320 (95% CI, $5863-$6777) for minor complications to $56 845 (95% CI, $47 953-$65 737) for major complications. The rates of complications after invasive diagnostic procedures were higher than the rates reported in clinical trials. Physicians and patients should be aware of the potential risks of subsequent adverse events and their high downstream costs in the shared decision-making process.