That is because we have finally updated from ICD-9-CM to ICD-10-CM. More on that later.
All you really need to know is that ME remains in the chapter on neurology at the classification G93.3, along with postviral fatigue syndrome (which is a British name that has not been used much, if at all, in the United States). CFS "remains" (from CDC's perspective) in a different chapter for vaguely defined symptoms at R53.82. However, the rest of the world (which has been using ICD-10 for 1-2 decades now) has CFS coded to G93.3 with M.E. So what appears not to be a change actually IS a change, and a significant one. How did we end up to be the only nation in the world who codes "CFS" under "General symptoms and signs: Malaise and fatigue"?
Let's start with some history.
The World Health Organization (WHO) puts out an International Classification of Diseases, and has done so since World War II. For more information, go to: WHO: International Classification of Diseases (ICD).
WHO's ICD's have gone through 10 revisions and they are now working on ICD-11.
In the 1980s, there were a series of cluster outbreaks throughout the United States of a disease that was probably Myalgic Encephalomyelitis (ME) - except that the name and diagnosis was not used in the US. First the outbreaks were labeled Chronic Epstein-Barr Virus (CEBV), because a lot of cases seemed to start with mono, but that theory was soon discarded by NIH's point man on EBV, Stephen Straus. He then began using the phrase "the chronic fatigue syndrome" to identify the outbreaks in internal memos in 1986.
CFS convened a committee in 1988 to rename and define CEBV. There were specialists at the meeting who insisted the outbreaks were really cases of ME, but neither Gary Holmes from CDC, nor Straus from NIH, paid any attention to that. ME is not mentioned in either the body or footnotes of the resulting article, which became known because it gave the first definition for CFS: Holmes (1988).
The name and concept CFS was thus thrown out to the world in 1988. At the time, WHO was on ICD-9 (the 9th revision), but was no longer making changes to ICD-9 because they were getting ready to roll out ICD-10. And ICD-10 was released to the world in 1992.
Since CFS was not in ICD-9, as long as the US continued to use it, they were free to place CFS wherever they wanted. The US uses a modification of ICD-9 called ICD-9-CM (for "clinical modification"). In 1997, the US placed CFS in 780.71, under "Symptoms, Signs, and Ill-Defined Syndromes" in ICD-9-CM. And there it has remained for almost 20 years.
In the meantime, the rest of the world was adopting ICD-10. By 2000, most were using it, including the UK.
Myalgic Encephalomyelitis (ME) has been in WHO's ICD codes since 1969, when it was first placed under neurology. The British had been using the name and diagnosis ME for almost 15 years by then. It had briefly begun as "benign" Myalgic Encephalomyelitis in the mid-1950s, when there were three major cluster outbreaks in the UK (replacing the name atypical polio that had been in use, along with a few other terms, since 1934). "Benign" had been stuck on the name because people were not dying in the streets from it, but the word was quickly discarded: As Melvin Ramsay, who went on to write two textbooks on ME, commented, there was nothing "benign" about ME! For some reason, when WHO first coded ME, they included "benign" in the name, and it's still there, although nobody else uses it.
ME is coded in ICD-9 and ICD-9-CM at 323.9 under neurology. It remained there in ICD-10, at G93.3, but it took second place in that category to post-viral fatigue syndrome, or PVFS (briefly fashionable as a diagnosis). CFS was never placed in the tabular, or more formal version of ICD-10 - however, it was placed in the index, and there it is coded to G93.3.
Canada, like the US, uses its own version of ICD-10, called ICD-10-CA. Since there were physicians in Canada who diagnosed ME, and physicians who diagnosed CFS, for what appeared to be the same disease, the Canadians placed CFS in the tabular version with ME at G93.3 when they adopted ICD-10-CA in 2001. The Canadian Consensus Criteria, which has been very popular in the ME and CFS community, was created by a committee convened by the National ME/FMS Action Network of Canada in 2003 in response to the blending of M.E. and CFS in G93.3 - and that is why the document uses ME/CFS throughout.
But while the rest of the world had long converted to ICD-10, the US remained on ICD-9-CM. One explanation is that hospitals and medical clinics protested the planned adoption of ICD-10-CM in the early 00's because it would be expensive. (Why they thought it would be easier later is a mystery to me.) The US has remained on ICD-9-CM 23 years after WHO adopted ICD-10 - and today, as we have just shifted to ICD-10-CM, WHO is within a couple of years of adopting ICD-11.
The agency responsible for the ICD-(whichever)-CD's in the US is the National Center for Health Statistics (NCHS) within CDC. (And that is where you will find the Official Version of ICD-10-CM.)
Advocates in the US had expected CFS to be moved to G93.3 in ICD-10-CM - indeed, when Donna Pickett of NCHS first presented the proposed changes to ICD-10-CM to CFSAC, that is where she said it would go. However, the late William Reeves, who ran CDC's program on CFS, was visibly distressed by this. According to Reeves, the only way he knew to diagnose CFS was to start with chronic fatigue and then distill it further into chronic fatigue syndrome. He could not do that if it was classified at G93.3 - and, furthermore, he did not believe the condition was neurological in nature.
So Pickett returned to CFSAC, and this time she suggested two classifications for CFS - CFS (postviral) would be placed in G93.3, and CFS (NOS) at R53.82 - in the chapter "General symptoms and signs," further characterized as "Malaise and fatigue." NOS stands for "not otherwise specified," in reference to CFS (postviral) in G93.3. The R53.82 was roughly equivalent to 780.71 in ICD-9-CM, so Reeves was satisfied.
However, soon word came out (and I don't know from whom) that CFS (postviral) was really the same thing as post-viral fatigue syndrome (PVFS), so CFS (postviral) was dumped from the draft of ICD-10-CM. That meant there was only ONE code for CFS - R53.82, CFS (NOS). It was peculiar that they retained "NOS" after deleting the only other code ever specified for CFS in ICD-10-CM. But there it is.
CDC, NCHS, Reeves, and his replacement Elizabeth Unger, all insisted that placing CFS in R53.82 meant they were not "making a change" to the code for CFS. Well, that was certainly the perspective from the US.
But the ICD codes do not originate in the US. They originate at the multinational organization WHO. And R53.82 represents a significant change from the coding used by WHO's ICD-10, G93.3 - a code accepted by more than one hundred nations. To say it hasn't changed is both disingenuous and self-centered.
In the meantime, in the late 1990s, the UK was having its own problems with the G93.3 code for CFS. British psychiatrists who had made their careers portraying CFS as a somaticizing (psychosomatic) disorder, specifically Simon Wessely and Peter White, wrote in textbooks that CFS was really "neurasthenia" (a "nervous disorder," once known as "the vapors" ...), and should be coded in F48.0 with neurasthenia under the chapter on psychiatry.
The Countess of Mar in Parliament protested the equation of CFS (and by extension, ME) with neurasthenia. Andre L'Hours of WHO responded with a letter to Parliament stating that it was against WHO's regulations for signatory nations to move a disease into a different chapter (after all, the purpose of the ICD codes was to be able to coordinate information on diseases internationally). Parliament told the British psychiatrists to issue an errata slip, which they did ... but the next year the same dance was repeated.
Earlier this year, when the Institute of Medicine at the National Academies of Sciences in Washington issued an NIH-commissioned report on the name and definition for CFS, they explicitly rejected codes that placed CFS in the "R" chapter, and codes that placed CFS with neurasthenia. That presumably left G93.3, but they did not make that explicit. CFSAC (the Chronic Fatigue Syndrome Advisory Committee at HHS) did make it explicit, and stated that the name M.E. should be used and the disease placed in G93.3 until we knew more about it. CFSAC has been making that suggestion since 2004, when they advised HHS to adopt 323.9 in ICD-9-CM (the equivalent of G93.3 in ICD-10) and also adopt the Canadian Consensus Criteria. HHS has not responded.
Well, there we are. The US has apparently violated WHO's rules about placing a disease in a different chapter by using R53.82 - more to the point, it is simply cruel to the one million patients suffering from this serious disease - as debilitating as MS, end-stage renal disease, cancer, and AIDS - as merely afflicted by something vaguely termed "malaise and fatigue." Furthermore, the R category is what is known as garbage diagnoses - conditions that are characterized by what they are not, not what they are. CFS (Fukuda 1994), M.E. (Canada 2011), and the latest incarnation, SEID (IOM 2015) can all be positively diagnosed by what they ARE. In fact, there is substantial evidence of immunological, neurological, and cardiological damage. There is evidence of chronic viral assaults. There are biomarkers being used by specialists today. (For the biomarkers that my own specialists have used, see my blog post from May 12, 2014: My 20 years with Myalgic Encephalomyelitis.)
But this is really nothing new. It is the same old same old. It is CDC being CDC. It has been 27 years since CDC adopted "chronic fatigue syndrome" for the name of this disease - and even CDC admits there are at least 850,000 adult Americans who have the disease but have no diagnosis. Many of these are people of lower income and people of color. I think it is a damning admission of failure.
So is the code R53.82.