Generates risk estimates and comorbidity flags from ICD-9-CM codes available in administrative medical datasets. The package supports the Charlson Comorbidity Index, the Elixhauser Comorbidity classification, the Revised Cardiac Risk Index, and the Risk Stratification Index. Methods are table-based, fast, and use the 'plyr' package, so parallelization is possible for large jobs. Also includes a sample of real ICD-9 data for 100 patients from a publicly available dataset.