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The ICD-10-AM/ACHI/ACS classification system is comprised of the following disease and intervention classifications: 

  • International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification (ICD-10-AM) used to classify diseases and other health problems
  • Australian Classification of Health Interventions (ACHI) used to classify procedures and interventions
  • Australian Coding Standards (ACS) specifies coding standards that provide guidelines to assist users of the classifications in obtaining consistency in clinical coding nationally.

ICD-10-AM/ACHI/ACS is used in public and private hospitals in Australia to classify episodes of admitted patient care. These classifications are currently updated every two years to ensure they are fit for purpose and remain clinically current.

Classification of Diseases

The International Statistical Classification of Diseases and Related Health Problems (ICD) is the foundation of health statistics. The tenth revision of ICD (ICD-10) is an alphanumeric classification and contains codes for diseases, signs and symptoms, abnormal findings, social factors and external causes of mortality or morbidity. In Australia, ICD-10 is used to classify causes of death.

Developed by the World Health Organization, ICD sets the international standard for reporting diseases and health conditions. It is used globally by clinicians, clinical coders, policymakers, researchers and many others. 

It is also used to monitor the health of a population, to plan how health services are delivered and detect changing disease patterns.

ICD-10 Australian Modification

The International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification (ICD-10-AM) is an expanded version of the World Health Organization’s ICD-10.

It consists of a tabular list of diseases and an accompanying index. 

ICD-10-AM is developed with assistance from clinicians, health information managers and clinical coders to ensure that the classification is current and appropriate for Australian clinical practice. It has been in use since 1998.

It uses an alphanumeric coding scheme for diseases and external causes of injury. It is structured by body system and aetiology and comprises three, four and five character categories. 

ICD-10-AM is updated on a regular basis, incorporating updates of WHO’s ICD-10 as part of this process.

Australian Classification of Health Interventions

The Australian Classification of Health Interventions (ACHI), previously known as the Medicare Benefits Schedule-Extended, is based on the Medicare Benefits Schedule (MBS) and further expanded to cover interventions not part of the MBS. This classification is structured by body system, site and intervention type, and consists of a tabular list of interventions and an accompanying alphabetic index.

This classification is structured by body system, site and intervention type, including interventions not currently listed in the MBS such as dental, allied health interventions, cosmetic surgery. 

ACHI codes have seven numeric digits. Where an intervention has an MBS equivalent, the first five digits are the MBS item number, followed by a two-digit extension representing specific interventions included in that item. 

ACHI was developed with assistance from specialist clinicians and clinical coders and has been in use since 1998.

Where an intervention does not have an MBS equivalent, such as allied health interventions, a new five digit code from the ‘90000’ series is used. In addition, some services from the Australian Schedule of Dental Services have been incorporated into ACHI into the ‘97000’ series.

Australian Coding Standards

The Australian Coding Standards (ACS) have been developed to support sound coding convention for use with ICD-10-AM and ACHI. They apply to all public and private hospitals in Australia.
The ongoing revision of the ACS ensures that they reflect changes in clinical practice, clinical classification amendments and various user requirements of admitted patient data collections.

Use of the classifications

Coded data using ICD-10-AM/ACHI/ACS underpins the Australian Refined Diagnosis Related Groups classification (AR-DRGs). 

The process of classifying or 'coding' involves the translation of information (diagnoses and interventions) from the patient health record into alphanumeric codes within ICD-10-AM and ACHI.

At the conclusion of a patient's episode of care, a clinical coder reviews the patient's healthcare record (the primary source of data for coding) and abstracts information recorded by clinicians to assign codes for the principal diagnosis, additional diagnoses and interventions performed in accordance with the ACS guidelines.

As coded data is used for multiple purposes, it is essential that coding is accurate and consistent with guidance provided in the ACS to produce meaningful statistics.

Users of the classification system include clinical coders, clinicians, researchers, epidemiologists, public health officials, state and territory health agencies, health funds, public and private hospitals, health economists and statisticians. 

Requests for content change

You can suggest changes to the AR-DRG and ICD-10-AM/ACHI/ACS classification systems via a public submissions process through the Australian Classification Exchange (ACE)

We encourage you to learn more about the requirements and process before lodging a submission. 

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