Quality & Practice

ICD-10 Codes - New Look, New Features

The International Classification of Diseases, 10th Edition Procedure Coding and Clinical Modification-ICD-10-CM was implemented in offices, hospitals, and medical centers across the United States on Oct. I, 2015. Even though this "new" version was developed more than 20 years ago and has been in use in other countries for well over a decade, the United States was slow to embrace and implement it fully. Time and space have simply run out in the previous edition widely known as ICD-9.

At the time it was replaced in 2015, ICD-9 was more than 30 years old and no longer reflected advances in medical knowledge or technology. It did not have any more room to grow to adapt to these advances and has reached its capacity at 14,000 codes. ICD-10-CM, on the other hand, has ample room to grow to approximately 68,000 codes. This dramatic increase in codes is due to greater flexibility with the use of 3-7 characters per code. The first code character is an alpha code and, therefore, codes have been tailored to be more specific in identifying a precise diagnosis. Each code can be divided into 3 parts to denote its specificity:

  • Characters 1-3: Category
  • Characters 4-6: Etiology, anatomic site, severity or other clinical detail
  • Character 7: Extension

ICD-10 codes have some additional features that enhance their specificity, including laterality, code extensions for injuries and external causes of injuries, and combination codes for diagnosis and symptoms. Taking all these characteristics into account, we can see how codes work by looking at the following examples:

  • S52: Fracture of forearm​
  • S52.5: Fracture of lower end of radius ​
  • S52.52​: Torus fracture lower end of radius​
  • S52.521​: Torus fracture of lower end of right radius​
  • S52.521A​: Torus fracture of lower end of right radius, initial encounter for closed fracture ​

Additional benefits of ICD-10 include better data for measuring quality, safety and efficacy of care, improvement in conducting research, epidemiological studies and clinical trials, improving clinical, financial and administrative performance, and preventing and detecting health care fraud and abuse.

The International Classification of Diseases Procedure Coding System 10th Edition (ICD-10- PCS) also took effect on Oct. 1, 2015. This portion of ICD-10 is unique to the United States and replaced ICD-9 volume 3. These sets of codes are only utilized for hospital inpatient coding and do not replace CPT in outpatient settings. These code sets have also experienced growth, going from approximately 4, 000 to 87,000. Just like their ICD-10-CM counterparts, the ICD-10-PCS codes are alphanumeric and seven characters long. They provide greater detail to describe complex medical procedures, and they describe exactly what has been done to the patient. ICD-10-PCS code structures are detailed in the following manner:

  • Character 1: Name of Section
  • Character 2: Body System
  • Character 3: Root Operation​
  • Character 4: Body Part
  • Character 5: Approach
  • Character 6: Device
  • Character 7: Qualifier  

For example, right knee joint replacement would be OSRCOJZ:

  • O = Medical Surgical Section
  • S = Lower Joints
  • R = Replacement
  • D = Knee Joint, Right
  • O = Open
  • J = Synthetic Substitute
  • Z = No qualifier

Every effort has been made to ensure the accuracy of PM&R In Practice. The content does not imply endorsement by nor official policy of AAPM&R. The official policies and specific resources of all governmental agencies and other professional organizations should be looked at by the reader. Helpful resources for more information include the CMS website, AMA CPT Book, and the ICD-9-CM code book. The information provided is not intended to be legal advice, but merely conveys general information related to legal issues commonly encountered. Nothing provided herein should be used as a substitute for the advice of competent legal counsel.