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ICD-9 vs. ICD-10

ICD-9 vs. ICD-10

The ICD, or International Statistical Classification of Diseases and Related Health Problems, is a standardized index of codes published by the World Health Organization (WHO). It applies specifically to medical coding of diagnosis. ICD standardizes the way diseases and diagnoses are coded and recorded as part of a patient’s electronic personal health information (ePHI). ICD-9 was adopted in the 1970s and the most recent revision, ICD-10, was completed in 1992. When comparing ICD-9 to ICD-10, ICD-10 adds over 130,000 new codes for new classifications of diseases and medical conditions.

Important Updates

There are several outstanding differences between the two most recent versions of ICD. In many ways, ICD-9 is incredibly limited in its ability to adequately name and describe medical conditions. ICD-10 has increased the number of codes almost tenfold, allowing for greater versatility and accuracy in describing new medical phenomena. These additions allow medical specialists around the world to share observations and diagnoses much more efficiently than in the past.

Some important updates that have been included in the release of ICD-10 include:

  • More efficient coding for mortality and morbidity statistics
  • More accurate and up-to-date terminology for diseases
  • More efficient tracking of trends and data
  • Improved ability to file claims efficiently
  • Increased protections against information abuse or fraud


The Health Insurance Portability and Accountability Act, known as HIPAA, requires that all practices transferring data electronically adopt certain standard practices. In addition to imposing penalties for failure to provide adequate protection, other penalties may be imposed for failure to adopt the required standard coding indices.

This includes both the Current Procedural Terminology (CPT) for electronic medical billing to insurance companies as well as ICD for diagnostic and statistical electronic medical coding. Under HIPAA, the deadline for adoption of ICD-10 has been delayed several times but the most recent deadline is October 1, 2015. Failure to demonstrably adopt ICD-10 can result in steep financial consequences.

Format Differences

There are a number of differences in format between the two versions of ICD. One such difference is the alphanumeric codes. In ICD-9, the codes consist of three to five letters and numbers. In ICD-10, there can be as many as seven digits which give index more versatility. Other differences include thousands more codes available for diagnosis which gives ICD-10 better accuracy in diagnosing conditions. ICD-10 also provides a more efficient method of adding codes.

These differences can be hard to understand or implement but the team of Certified Coders at Quest National Services provides expert advice and resources to make the transition as smooth as possible. Quest National Services’ coders have been certified in ICD-10 since January 2014 and have been providing guidance to providers nationwide since March 2014 in preparation for the transition from ICD-9 to ICD-10.