Background Identifying iatrogenic injuries using existing data sources is important for improved transparency in the occurrence of intraoperative events. There is evidence that procedure codes are reliably recorded in claims data. The objective of this study was to assess whether concurrent splenic procedure codes in patients undergoing colectomy procedures are reliably coded in claims data as compared with clinical registry data. Study Design Patients who underwent colectomy procedures in the absence of neoplastic diagnosis codes were identified from American College of Surgeons (ACS) NSQIP data linked with Medicare inpatient claims data file (2005 to 2008). A κ statistic was used to assess coding concordance between ACS NSQIP and Medicare inpatient claims, with ACS NSQIP serving as the reference standard. Results A total of 11,367 colectomy patients were identified from 212 hospitals. There were 114 patients (1%) who had a concurrent splenic procedure code recorded in either ACS NSQIP or Medicare inpatient claims. There were 7 patients who had a splenic injury diagnosis code recorded in either data source. Agreement of splenic procedure codes between the data sources was substantial (κ statistic 0.72; 95% CI, 0.64-0.79). Medicare inpatient claims identified 81% of the splenic procedure codes recorded in ACS NSQIP, and 99% of the patients without a splenic procedure code. Conclusions It is feasible to use Medicare claims data to identify splenic injuries occurring during colectomy procedures, as claims data have moderate sensitivity and excellent specificity for capturing concurrent splenic procedure codes compared with ACS NSQIP.