©Marilyn Kerr RN March 4, 2001

What are ICD codes?

The World Health Organization, with input from every country, assigns diagnostic codes for illnesses/diseases/symptoms/procedures and compile them into the "International Classification of Diseases" (ICD) manual. When the WHO revises a current manual and/or publishes a new one, they are offered to each country.

The WHO and most of Europe are presently using the latest "book," the ICD-10.

Any country can take the WHO ICD manual and revise them in any way they wish or accept them in totality. The US (as well as other countries) has either assigned the same codes, modified the WHO ICD by adding more delimiters, or deleted particular ICD codes totally.

Are there different versions of the ICDs?

There is the "master" WHO ICD manual and then a separate one prepared by each country. The physicians within each country are required to use that country's ICD manual.

The diagnostic codes used in the US have to comply with those enacted by the United States government.

When was the last revision to the ICD-9?

The US is presently using the ICD-9 with its Ninth revision dated October 1999. According to the American College of Physicians, American Association of Internal Medicine Journal, there were no changes made in the October 2000 revision. The US is at least two years overdue in implementing the US version of the ICD-10.

Who decides what becomes a diagnostic code in the US?

In the US, it's done by taking input from the federal government which includes the CDC, it's "Morbidity and Mortality Weekly Report," the HCFA (which administers Medicare and oversees Medicaid), the National Center for Health Statistics, Department of Defense, Department of Veterans Affairs, the US private insurance carriers, and the state governments to determine which diseases, syndromes, symptoms, procedures, etc. are relevant to the US population.

What are the diagnostic codes for CFS, FM, CFIDS, ME, and Lyme Disease?

The current US version of the ICD-9 has no diagnostic code for ME. The 323.9 that was utilized by some patients was based on an out-dated revision. 323.9 is now "encephalitis, myelitis, encephalomyelitis, non-specified."

The 323.9, based on the CDC instruction manuals for the upcoming ICD-10, will become the US ICD-10 O43.1, and will be included within the O42.0 through O44.9 HIV classification codes.

In searching the German ICD-10 site, there wasn't ME in any form. However, it was in the German ICD-9 as "benign myalgic encephalitis/encephalomyelitis" with the above mentioned ICD of 323.9.

CFS is in the current US ICD-9 as 780.71. In the prior revision of October 1998, it had been dropped entirely, but was returned in the October 1999 revision. Apparently it will become G93.3 in the US ICD-10 (under the heading of "Other Diseases of the Nervous System") and, based on the German ICD-10 searchable site, has been adopted as such elsewhere. G93.3 will also include Post Viral Syndrome.

Myalgic encephalitis/encephalomyelitis (ME) is not a current US ICD-9 designation. Based on the CDC's instruction manual, it apparently is not going to be included in the US ICD-10.

Fibromyalgia Syndrome was deleted entirely in October 1999 and that code (729.1) now is identified it as "myalgia and myositis, unspecified, fibromyositis."

There is no ICD for CFIDS because it has not been recognized by any decision-making government organization. If one's doctor is using CFIDS as a diagnosis, check to insure that the diagnostic code attached to it is 780.71.

Lyme Disease is now 323.3 and will become O63 in the ICD-10.

What are the implications of diagnostic codes?

Why is this important? It becomes crucial when one is applying for disability because the Social Security and the Long-Term Disability carriers check the charts to see which ICDs have been assigned. For instance, if one is trying to obtain disability for CFS (780.71) but the doctor (through his staff) has categorized the patient in the "chronic fatigue" (780.79) category, one's going to have an uphill battle.

And if one is assigned a diagnostic code not used in the US, it will be ignored/rejected unless there are appropriate documentation to back up the symptoms (and then the insurance carrier *may* change it to a more appropriate US ICD code).

Like the insurance carriers, Medicare will reject any claims with an invalid diagnostic code.

It's also just as important in trying to get insurance companies to pay for services - the ICD code must be correct.

Additionally, ICD codes are used in research projects and for keeping statistics on that disease, illness, syndrome, and/or procedure. For instance, by the US government deleting Fibromyalgia Syndrome as a diagnosis in 1999, up to 10 million Americans with this syndrome are no longer being accounted for by insurance carriers and the government. So, despite being told by their doctors that they have FM, their diagnosis doesn't "exist" to their insurance company.

What are the sites that have current ICD information?

Among the various sites to find the current US ICD codes for any disease/syndrome (or, in reverse, by entering the code, what disease/syndrome has been assigned) are the following:
http://eicd.com. If requested to "log-in," simply entered a ten-digit telephone number.
http://www.mcis.duke.edu/standards/termcode/icd9/. No Registration needed.
The URL of German ICD9-ICD10 search engine is: http://icd.web.med.uni-muenchen.de. In German, but most English words will work.

There are files one can find on the CDC website which show how the US is changing, accepting, or rejecting each individual diagnostic code of the WHO's ICD-10. These instruction manuals for the upcoming US ICD-10 can only be found by searching at the CDC site (http://www.cdc.gov) for "2amanual" and "2emanual." You will need Adobe Reader to be able to decipher those documents.

Because of the community's interest in this subject and to help dispel inaccuracies one may encounter online, I will try to keep this page updated.

Any questions that can't be answered at the above sites, or to offer corrections, feel free to write me at this address.

Index of CFIDS/FMS Info Pages

Since July 2, 2001