ICD-9-CM versus ICD-10CM – What’s the Difference for Medical Billers?

ICD-codes are diagnosis codes. Today, most of the ICD codes used in the United States are version 9, which are called ICD-9-CM codes. However, by October of 2015, ICD-10 will be the system used. Many countries in the world have implemented the ICD-10 codes but the USA has fallen a bit behind in this endeavor.

There certainly are major differences between ICD 9 and ICD 10 codes. The ICD-10 diagnosis and procedure coding system is more complex than ICD-9 coding, but it will allow for a greater level of specific detail and will be better able to keep pace with advances in technology.

What’s the Difference for Medical Billers?

ICD-9 codes  have three characters to the left of a decimal point, and one or two digits to the right of the decimal point. Some of these codes are preceded by a V or E.   ICD 10 codes are approached differently and are broken down into chapters and sub chapters. They consist of a letter plus two digits to the left of the decimal point, then one disease to the right. Diseases are grouped by letters here. For instance, if you are to code a malignancy (cancer), you’ll need to place a C in front of the code; similarly you’ll need to put a K to indicate gastrointestinal problems. It’s being expected that ICD-10 will have better data for evaluating and improving quality of care and will provide codes for a more complete picture.  So, the numbering system is a bit different, there are a lot more codes in ICD-10, and there will be a few guideline changes such as many etiology/manifestation codes will now be just one code.

It’s a good to choose a medical billing course at this point that does have training in ICD-10 as it is set to launch in the USA this next year.


By: Dawn Moreno, PhD, CBCS, CMAA, MTC. Lives in the beautiful Southwest United States and has been an instructor for medical coding/billing for the past 7 years. Interested in quality medical billing training?   Click Here for Medical Billing Tips

Know more about ICD-9-CM versus ICD-10CM – What’s the Difference for Medical Billers?

ICD 10 Coding | Crosswalking ICD 9 to ICD 10 – Video

AAPC – ICD 9 to ICD 10 Crosswalk (by specialty)

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