Effective Oct. 1, 2013, diagnostic coding in all health care settings will change from the International Classification of Diseases Ninth Revision (ICD-9) to the Tenth Revision (ICD-10). The biggest differences between ICD-9 and ICD-10 are:

  • There are more codes: ICD-10 has approximately 70,000 codes, while ICD-9 has approximately 14,000 codes.
  • The format is different: ICD-10 codes are all alpha-numeric and range from 3 to 7 characters, while ICD-9 codes are primarily numeric and are 5 digits or less.

To help facilitate the transition, General Equivalence Mappings (GEMs) have been developed to convert data from ICD-9 to ICD-10 and vice versa. For more information on the transition from ICD-9 to ICD-10 and for a full listing of the 2011 version of the GEMS, visit the CMS website.

Watch for “Part 2” of this article in two weeks, which will focus on claims submission and the transition to ICD-10