ICD-10 essentials for busy physicians who would rather be doing something else -- Diabetes and CHF

As promised, I am going to talk about chronic conditions that are common enough that most physicians see patients who have them. And that means dealing with the documentation needs for coding the patient encounter in ICD-9 now and ICD-10 in the future. In this blog I am going to highlight the similarities and differences between ICD-9 and ICD-10 documentation and coding needs for diabetes and congestive heart failure (CHF).

Diabetes coding will actually be easier and more efficient in ICD-10, which should translate into fewer queries from coders. There are two basic changes in ICD-10 diabetes classification:

  • No more coding and documentation hassles with uncontrolled diabetes.
  • Complex diabetes cases that required multiple ICD-9 codes can be coded with one ICD-10 code.

Like hypertension, diabetes classification in ICD-9 was unnecessarily complex because it used terminology that did not reflect the real world. In diabetes classification the culprit was a sub-category called uncontrolled diabetes. Physicians don’t use the term uncontrolled, and much time and energy was spent trying to figure out the circumstances under which these codes could be used.

ICD-10 does not contain any diabetes codes that use the term uncontrolled. If the words inadequately controlled, poorly controlled or out of control are used, that documentation translates to a code that specifies the diabetes by type and the fact that the patient currently is hyperglycemic. For example, a patient described as “Type 2 DM poorly controlled” is all the documentation needed for using ICD-10 code E11.65 Type 2 diabetes mellitus with hyperglycemia.

Patients with long-standing diabetes who have developed additional manifestations such as retinopathy often require additional separate ICD-9 codes in order to fully capture the complexity of a case. In ICD-9 this carries with it the risk that complex cases don’t get completely and accurately coded, and the coded data doesn’t accurately reflect how ill your patient actually is.

This situation has been improved in ICD-10, because many ICD-10 codes describe the diabetes plus many of the manifestations associated with complex cases in a single code. For example, a patient documented as “Type 1 diabetic with nonproliferative retinopathy and macular edema” can be completely described with a single ICD-10 code.

E10.321 Type 1 diabetes mellitus with mild nonproliferative diabetic retinopathy with macular edema


250.51 Diabetes with ophthalmic manifestations, type I [juvenile type], not stated as uncontrolled  
362.04 Mild nonproliferative diabetic retinopathy 
362.07 Diabetic macular edema

There are no documentation changes for type 2 diabetes without any complications or other manifestations.

E11.9 Type 2 diabetes mellitus without complications  


250.00 Diabetes mellitus without mention of complication, type II or unspecified type, not stated as uncontrolled  

Congestive heart failure
Heart failure documentation for ICD-9 got more complicated a few years ago when specific codes were added classifying heart failure by the clinical subtypes acute/chronic and systolic/diastolic, such as 428.22 Chronic systolic heart failure. In ICD-9, if one of these specific diagnoses was documented in addition to the fact that the patient has CHF, the coding looked like this:

428.22 Chronic systolic heart failure
428.0 Congestive heart failure, unspecified

This is yet another example where ICD-10 is actually more streamlined than ICD-9, and therefore more likely to be correctly coded. (The term congestive in the context of such very specific heart failure codes is a non-essential modifier in ICD-10, which is just a fancy way of saying it doesn’t need to be recorded in a separate code, because it is already included in the meaning of the code.)

Since heart failure is not always documented in such detail, the code subtypes specifying acute/chronic and systolic/diastolic don’t get used as much as the unspecified CHF code by itself. But if you do make the effort to document heart failure in this way, the good news is that the terminology used in ICD-10 is exactly the same. So whatever you have done to adjust documentation to the requirements of ICD-9, they are no different in ICD-10. And, CHF is not required to be coded separately in ICD-10, in addition to the very specific heart failure code. The ICD-9 code pair above rendered in ICD-10 looks like this:

I50.22 Chronic systolic (congestive) heart failure

As with ICD-9, the “acute on chronic” heart failure classification describes patients with diagnosed CHF who are having an acute exacerbation/decompensation. Here is what they look like in ICD-10.

I50.23 Acute on chronic systolic (congestive) heart failure
I50.33 Acute on chronic diastolic (congestive) heart failure
I50.43 Acute on chronic combined systolic (congestive) and diastolic (congestive) heart failure

“Decompensation” or “exacerbation” documented on the record in some form correlates to the concept of “acute” as used in ICD-10 without any additional documentation or queries from the coder. 

A patient who is described as “on Lasix for CHF” is correctly documented as is for using the ICD-10 code below.

428.0 Congestive heart failure, unspecified


I50.9 Heart failure, unspecified

Next blog I plan to compare ICD-9 and ICD-10 coding and documentation needs for asthma and COPD, and would love to hear from you if you have any suggestions. Thanks for reading.

Rhonda Butler is a senior clinical research analyst with 3M Health Information Systems. She is responsible for the development and maintenance of the ICD-10 Procedure Coding System since 2003 under contract to CMS, and for the development and maintenance of the ICD-10 General Equivalence Mappings (GEMs) and Reimbursement Mappings under contract to CMS and the CDC.  She leads the 3M test project to convert the MS-DRGs to ICD-10 for CMS, and is on the team to convert 3M APR-DRGs to ICD-10. Rhonda also writes for the 3M Health Information Systems blog.