Home Coding New and revised ICD-9 codes hospitalists need to know

New and revised ICD-9 codes hospitalists need to know

If you haven’t heard about these changes, which took place in October, you’re already a step behind

December 2005

Published in the December 2005 issue of Today’s Hospitalist

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We once again find ourselves at the end of another calendar year, and we once again face more major changes to ICD-9 codes. In all, there are 144 new codes that physicians must now choose from to document their services, and many apply to hospitalists.

Some of these new codes will help you be more specific when documenting common conditions like dehydration, hypoxia, chronic kidney disease, and obesity. There are also many revisions to the language that ICD-9 codes use to describe conditions like insomnia, muscle weakness, and myocardial infarction.

While I’ll point out changes to codes that you need to know about as a hospitalist, there is another even more important change to all ICD-9 codes that affects all physicians. In the past, the Centers for Medicare and Medicaid Services (CMS) gave physicians and coders a few months’ time to get used to new code sets. Changes would be announced in October, but physicians wouldn’t be required to use them until the first of the following year. That gave all of us a window of opportunity to update our systems and educate clinicians about the changes.

Now, however, the CMS has taken away that transitional period and expects all physicians to implement new and revised ICD-9 codes as of Oct. 1, 2005. This means that you should start using all the new codes outlined here immediately.

Here’s a look at new ICD-9 codes and definitions commonly used by hospitalists.

Chronic renal failure

In the past, we used ICD-9 code 585 to refer to chronic renal failure. This all-purpose code encompassed all end-stage renal disease patients, as well as chronic uremia.

With the recent changes, however, we must now use the following codes:

  • 585.1: chronic kidney disease; stage I.
  • 585.2: chronic kidney disease; stage II.
  • 585.3: chronic kidney disease; stage III.
  • 585.4: chronic kidney disease; stage IV (severe).
  • 585.5: chronic kidney disease; stage V.
  • 585.6: end stage renal disease.
  • 585.9: chronic kidney disease; unspecified.

Do not simply use the unspecified code as a default. You must document the severity of the kidney disease.


Until now, the ICD-9 code for hypoxia was 799.0. That has changed to the following two new codes, which provide a higher level of specificity:

  • 799.01: asphyxia.
  • 799.02: hypoxemia.


In 2005, ICD-9 code 276.5 was all that you needed to use to note volume depletion. We now must use the following three codes to provide more detail:

  • 276.50: volume depletion, unspecified.
  • 276.51: dehydration.
  • 276.52: hypovolemia.


Before the current revisions, there were two codes for obesity:
278.00 for unspecified obesity and 278.01 for morbid obesity. There is now a new ICD-9 code “278.02 “to refer to overweight patients.

Myocardial infarction

The 410 family of ICD-9 codes referring to myocardial infarction has a new elaboration in its definition. ICD-9 codes in this group now refer to “ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction.”

You must still specify the wall in which the MI occurred, and you need to list a fifth digit to note whether the MI was an initial episode of care (xxx.x1), a subsequent episode of care (xxx.x2), or unspecified (xxx.x0).

Here are the revised definitions:

  • 410.0: anterolateral wall-ST elevation MI.
  • 410.1: other anterior wall-ST elevation MI.
  • 410.2: inferolateral wall-ST elevation MI.
  • 410.3: inferoposterior wall-ST elevation MI.
  • 410.4: other inferior wall-ST elevation MI.
  • 410.5: other lateral wall-ST elevation MI.
  • 410.6: posterior wall-ST elevation MI.
  • 410.7: subendocardial infarction-non-ST elevation MI.
  • 410.8: other specified sites-ST elevation MI.
  • 410.9: unspecified site.


There have been some minor wording changes to ICD-9 code 780.52. While the description of this code previously referred to “other insomnia,” it now refers to “insomnia, unspecified”.

Muscle weakness

In describing muscle weakness, ICD-9 code 728.87, be aware that the word “generalized” has been added to the definition. Do not confuse this revised language with the ICD-9 code for overall body weakness and fatigue, which remains 780.79.

With diagnosis coding, it is always recommended to be as specific as possible. It won’t guarantee more reimbursement, but will help expedite the reimbursement by avoiding unnecessary denials.

tamaraTamra McLain is coding manager for HRA Medical Management Inc. in San Diego. E-mail her your documentation and coding questions or send a fax to 619-280-1347. We’ll try to answer your questions in a future issue of Today’s Hospitalist.