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ICD-11 Monthly – October 2023

Comparing Codes Across ICD Versions: Heart Failure

In this month’s ICD-11 deep dive, UASI’s Mary Stanfill continues to examine the differences between ICD-10 and ICD-11 to get a feel for how these changes will impact day-to-day coding.

The WHO ICD-11 classification is very different from the 10th version that the United States modified to create the ICD-10-CM code set that is used for reporting healthcare services on claims in the US today. The WHO began development of ICD-11 in 2007 and it was formally adopted in 2019 for implementation world-wide beginning in 2022. In contrast, ICD-10 was first released in 1992. And, though the US finally implemented ICD-10-CM in 2015, the ICD-10 classification it’s based on is nearly 25 years old.

In monthly code comparisons, we’ve looked at codes that are pre-coordinated or post-coordinated in ICD-11 and compared them with the most closely associated pre-coordinated ICD-10-CM codes. This month we look at one example of how terminology and definitions have been updated in ICD-11.

Below are the codes for chronic diastolic heart failure in both ICD-11 and ICD-10-CM.


  • These code assignments reflect the closest equivalent code from each code set as of October 2023.
  • Code category comparisons reflect excerpts from the ICD-11 MMS Browser compared to segments from the ICD-10-CM Tabular listing.
  • Only the codes in bold are complete (valid) codes. Nonbolded codes require additional characters.

According to the WHO ICD-11 MMS, diastolic heart failure, by definition, is left ventricular failure with preserved ejection fraction. Systolic heart failure is heart failure with reduced ejection fraction. The medical coder will need to be aware of these definitions for correct coding with ICD-11 (though code BD11.0 does specify the matching term “chronic diastolic congestive heart failure”). Post-coordination codes presented in the ICD-11 MMS include the causing condition (e.g., hypertensive heart disease, valve disease), severity (according to NYHA class I – IV), and the course (e.g., acute or chronic).

In comparison, the inclusion terms in ICD-10-CM are consistent with the ICD-11 MMS definitions. For example, diastolic heart failure has an inclusion term for heart failure with normal or preserved ejection fraction. However, the ICD-10-CM codes are indexed based on diastolic verses systolic, not preservation or reduction in the ejection fraction. ICD-10-CM also does not include any mechanism to capture severity of the patient’s symptoms, as reflected in the heart failure classes, which would be extremely useful to represent patient acuity. Today, we have focused on clinical documentation of diastolic verses systolic type of failure, with ICD-11 it will be important to document the impact on the ejection fraction.

If this makes you wonder how the other cardiovascular codes compare, I encourage you to visit the WHO website to browse ICD-11 codes or use the ICD-11 coding tool.

Mary H. Stanfill is Vice President of Consulting for United Audit Systems, Inc. and is the official representative of the IFHIMA to the WHO Family of International Classifications Education and Implementation (EIC) and Morbidity Reference Group (MbRG) workgroups. She has over 35 years of experience in the health information profession, primarily focused on clinical classification of healthcare data. She holds a masters in biomedical informatics and is currently pursuing a doctorate in health informatics.


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