ICD-11

ICD-11 has been developed in collaboration with clinicians, statisticians, classification and IT experts from around the world. It is substantially different from ICD-10 both in design and structure, to reflect the changing health environment and ensure the classification remains current. 

Features of ICD-11 

ICD-11 has features that provide significant advantages and opportunities:

• completely digital and designed to be interoperable in health information systems.
• reflects the latest advances in science and medicine. 
• includes new chapters for diseases of the immune system, sleep-wake disorders, conditions related to sexual health and traditional medicine and a new section for functioning assessment, aligned with WHO’s International Classification of Functioning, Disability and Health (ICF). 
• greater flexibility and applicability due to its structure and design. Subsets of codes (known as linearisations) can be created for different purposes. Linearisations may be specialised such as a linearisation for dermatology or have broad application such as a linearisation for admitted patient care or primary care. 
• introduces stem codes and extension codes: 
  • stem codes are codes that can be used alone and describe a clinical condition or entity. Extension codes are added (‘postcoordinated’) to stem codes and add further specificity or detail. 
  • extension codes are available for severity; temporality; aetiology; topology; anatomy and topography; histopathology; dimensions of injury; dimensions of external causes; consciousness; substances; diagnosis code descriptors; capacity or context; and health devices, equipment and supplies.
  • stem codes may also be postcoordinated with other stem codes which enables the linkage of core diagnostic concepts, for example pneumonia and sepsis; or diabetic coma and type 1 diabetes mellitus.
  • a group of postcoordinated codes is called a cluster.

Clustering in ICD-11

A cluster is a group of codes that when combined describe and fully characterise a clinical concept. The ampersand (&) or a forward slash (/) are used to combine codes. 

The ampersand (&) is used to postcoordinate extension codes and form a cluster. 

            stem code&extension code    

            stem code&extension code 1&extension code 2 

The forward slash (/) is used to postcoordinate stem codes and form a cluster.

            stem code 1/stem code 2

A cluster may include multiple stem codes and extension codes.

World Health Organization (WHO) Resources

ICD-11 Homepage

ICD-11 information page

ICD-11 Coding Tool 

ICD-11 Browser

ICD-11 fact sheet

Preparation for ICD-11 in Australia

ICD-11 has superseded ICD-10 and the WHO is no longer maintaining or releasing updates for ICD‑10. 

Currently in Australia, ICD-10 and the Australian modification ICD‑10‑AM serve multiple purposes. The classifications are used for data collection, reporting and analysis in: 

• epidemiology and research 
• monitoring of patient safety and the quality of health care 
• health service planning
• benchmarking
• activity based funding
• private health care.

Despite the advantages of ICD-11, it is a significant undertaking to replace a highly utilised classification such as ICD-10-AM due to it being embedded in so many elements of our health system. Before a decision to implement ICD-11 in Australia is made, the clinical, business and statistical implications will be assessed. 

Australia has successfully implemented new classifications previously, such as in 1998 when ICD-10-AM replaced the clinical modification of ICD-9 (ICD-9-CM). Whilst similar, the implementation of ICD-11 in Australia is expected to be a greater challenge due to the difference in structure and design between the two classifications, and the extended scope of content. 

Despite this challenge, IHACPA recognises the advantages of ICD-11 as health care continues to evolve and digitalise. Therefore, IHACPA is completing activities to help inform a decision on the implementation of ICD-11 in Australia. 

IHACPA activities  

Mapping ICD-10-AM to ICD-11

In 2023, IHACPA commenced a project to map ICD-10-AM to ICD-11. The project is technically a crosswalk as it is a comparison between two different classifications (ICD‑10‑AM and ICD-11). However, as the main goal is to produce a map between ICD‑10‑AM and ICD-11, it is referred to as a mapping project. The mapping project will identify equivalent codes, codes with greater or less specificity and codes that have no match, to determine where there are gaps and assess the additional features available in ICD-11. The mapping project is the first and most important step in IHACPA’s implementation framework for ICD-11 as a replacement to ICD-10-AM. 

The mapping project is expected to be completed in 2025. The findings may inform submissions to the WHO Maintenance Platform, where ICD-11 proposals are reviewed by the WHO Family of International Classifications Network. This will ensure ICD‑11 is suitable prior to an implementation decision for Australia.

The results will also be used to analyse the impact on casemix classifications such as those used in admitted acute care (Australian Refined Diagnosis Related Groups (AR-DRGs)) or emergency care (Australian Emergency Care Classification (AECC)). It will also be an opportunity to review other casemix classifications to determine if ICD-11 can be used to benefit these classifications.

Implementation of cluster coding

IHACPA is proposing the implementation of cluster coding in ICD‑10‑AM Thirteenth Edition. Cluster coding is an essential step in the preparation for ICD-11. Cluster coding also has benefits that can be realised in the short term, prior to ICD-11 implementation. 

• The staged implementation of cluster coding supports those involved in the clinical coding process to complete education and develop their knowledge of cluster coding ahead of the education and skill development required for ICD-11. 
• As coded data is tracked and used for research and epidemiological studies, it is important for the data between ICD-10-AM and ICD-11 to be comparable. Introducing cluster coding in ICD-10-AM improves how related conditions can be compared and tracked by data users between the classifications. 
• Clustering in ICD-10-AM helps the design and preparedness of health information systems and health infrastructure for ICD-11. 

• The new Australian Coding Standard 0004 Diagnosis cluster identifier (DCID) provides detailed guidelines for clinical coders on how to link related conditions in a cluster. The ability to cluster codes related to safety and quality events that occurred during the episode of admitted care enhances the value of the coded data. This also improves the accuracy of safety and quality reporting and reduces the reliance on manual review of health care records. 

  Learn more about cluster coding

  Last updated: 5 November 2024