Skip to main content

What is ICD-10?

Published Date
Author Leona Rajaee

iStock 165771189
What is ICD-10?

What is ICD-10? August 22, 2017

The International Classification of Diseases (ICD) actually began as the International List of Causes of Death, adopted by the International Statistical Institute in 1893. The World Health Organization (WHO) was entrusted with the ICD system in 1948, publishing the sixth edition as ICD-6.

ICD is, according to WHO, the “diagnostic classification standard for all clinical and research purposes.” ICD is designed for:

  • Easy storage, retrieval and analysis of health information for evidenced-based decision-making
  • Sharing and comparing health information between hospitals, regions, settings and countries
  • Data comparisons in the same location across different time periods.

Now in its tenth revision and known as ICD-10, the coding system is seen by many independent physicians as a source of stress and frustration. Though helpful for categorizing and tracking patient data, ICD-10 is a major shift from its predecessor, and as of October 2015, is mandated by the Centers for Medicare & Medicaid Services (CMS) as a replacement for ICD-9.

ICD-10 is more complicated and more specific. While the old ICD-9 codes used 3-5 characters consisting only of numbers, the new ICD-10 system uses codes with 3-7 characters in an alphanumeric combination, thus allowing for greater specificity in making diagnoses. ICD-9 did not have the specificity needed in many cases to enable the physician to identify, for example, whether a broken bone is in the right or left hand. In addition, most other countries had already transitioned to the ICD-10 system so the US mandate was effective in making coding systems compatible for collaboration internationally.

While helpful in identifying conditions and injuries, ICD-10 has been a challenge for many independent physicians. ICD-10 has approximately 69,000 codes compared to the 14,000 ICD-9 codes. Providers who use electronic health records (EHRs), however, have found that the transition from ICD-9 to ICD-10 seamless.

The ICD-10 mandate, according to CMS, is required for all medical providers subject to HIPAA regulations, not just to those who bill Medicare or Medicaid.