What is ICD-10?

ICD-10-CM is a clinical modification of the World Health Organization’s ICD-10, which consists of a diagnostic classification system. ICD-10-CM includes the level of detail needed for morbidity classification and diagnostic specificity in the United States. It also provides code titles and language that complement accepted clinical practice in the U.S. As with ICD-9-CM, ICD-10-CM is maintained by the U.S. National Center for Health Statistics.

When the US modified ICD-9 to create ICD-9-CM more than 30 years ago, a third volume was added to capture procedure codes. However, instead of appending a short volume to ICD-10-CM, a complete classification, ICD-10-PCS, was developed. This procedural coding system is much more detailed and specific than the short volume of procedure codes included in ICD-9-CM.

The ICD-10-CM system consists of more than 68,000 diagnosis codes, compared to approximately 13,000 ICD-9-CM diagnosis codes. ICD-10-PCS consists of 87,000 procedure codes. Together the ICD-10-CM and ICD-10-PCS codes have the potential to reveal more about quality of care, so that data can be used in a more meaningful way to better understand complications, better design clinically robust algorithms, and better track the outcomes of care. ICD-10-CM and PCS incorporate greater specificity and clinical detail to provide information for clinical decision making and outcomes research.