About SnoMAP Starter

The SNOMED CT-AU to ICD-10-AM SnoMAP Starter has been designed to provide a map to meet known and identified requirements of researchers/ analysts working with SNOMED encoded patient data collections where their analyses demand conversion to ICD-10-AM for comparability purposes; Either for retrospective analyses where only historical ICD-10-AM data is available, or for consolidated patient data collections that contain both SNOMED and ICD-10-AM encoded cases. 

This map: 

  • does not support mandatory reporting for National Minimum Data Standards (NMDS) data or for Casemix funding; Diagnosis Related Groups (DRG) or Activity Based Funding (ABF) and 
  • Is not designed to be used in any user facing, point-of-care deployments 

Design principles 

The map has been developed using these assumptions as design principles 

  • Assumes patient level data only 
  • Assumes diagnosis data only 
  • Allows for symptoms and less-than-formal diagnoses where ICD allows 
  • Allows for some Procedure content, where ICD allows 

Maps are provided for semantic meaning only and: 

  • Does not provide a rule or knowledge base 
  • Does not honour Australian Coding Standards (ACS) or National Minimum Data Standards (NMDS) requirements, not suited to (Computer – assisted coding) CAC 
  • Makes no assumptions about principal, additional, working, differential diagnoses 
  • Makes no assumptions about episodes, attendances, admissions or readmissions 
  • Makes no assumptions about the number or ordering of diagnoses 
  • Makes no assumptions about clinical coding standards 

Map content 

Contains maps from ~80K SNOMED CT-AU concepts to  ~10K ICD-10-AM codes 

  • Many to one, in a ratio of approx. 8:1 
  • Map type:  equivalence 
  • The map is not bi-directional – It only transforms from SNOMED CT-AU to ICD-10-AM (not from ICD-10-AM to SNOMED CT)  
  • All maps are ‘best semantic’ matches of the concepts defined in SNOMED CT-AU, associated with the coded categories that ICD-10-AM allows.  
  • Full historical maps are preserved from first release – 20200715 
  • Maps that become invalid between release versions are inactivated.  They are replaced per version, but not removed.  


The range of SNOMED concepts used in documenting patient cases (prospectively) in clinical practice cannot be predicted. It is often unconstrained, whereby clinicians can document using any or all SNOMED CT-AU concepts. This means that some SNOMED CT-AU encoded patient cases will (i) be erroneously encoded (ii) not valid diagnosis codes (iii) will never achieve a map to ICD-10-AM 

The scope of SNOMED CT-AU content in snoMAP Starter is determined by ICD-10-AM. If ICD-10-AM does not contain a place to map the SNOMED CT-AU concept to, then that concept is EXCLUDED from snoMAP.  If SNOMED CT-AU can’t find an equivalent in ICD-10-AM then there is no map. 

This map contains SNOMED CT-AU concepts from the following hierarchies: 

  • Clinical finding (~90% of maps) 
  • Event 
  • Situation with explicit context 
  • Procedure 


ICD-10-AM provides coding conventions, statistical sensitivity and mutual exclusivity and therefore determines how and which SNOMED CT-AU concepts are mapped.   

ICD-10-AM conventions that influence the content included in the map are: 

  • ICD-10-AM demands a formal diagnosis, and because it excludes other types of less formal diagnoses, and all non-diagnoses, some SNOMED concepts that appear in data collections cannot be mapped; ICD-10-AM disallows them. 
  • ICD-10-AM does not accept or provide codes for procedures, anatomy, substances, observational or diagnostic results; nor medication management.  
  • ICD-10-AM does not allow encoding of normal patient findings, such as Normal heart rhythm, well infant;  
  • ICD-10-AM does not encode for clinical practice activities, such as Referred to Social Worker, Follow-up in 2 weeks. 

Map maintenance 

SnoMAP Starter  will be updated/maintained on a quarterly basis and released in  January,  April*, July and October*. 

*The April and October releases are timed to ensure that SNOMED International updates are incorporated as soon as possible (as the NCTS releases them in March and September) 

New or amended editions of ICD-10-AM are usually released every two years. 

Maintenance will be performed based on: 

SNOMED CT-AU releases where: 

  • Existing map content is retired and replaced based on SNOMED CT-AU  
  • New SNOMED CT-AU content exists that is applicable to the map 

ICD-10-AM content in the map where: 

  • Content changes affect the map 
  • New map requests result in new maps 

Patient data collections may contain SNOMED CT-AU concepts that have not been mapped in SNOMAP Starter. 

Request new concept map 

New maps may be constructed for these SNOMED CT concepts, on request. 

If you would like to submit new content for this map, please email details to snomap@csiro.au  or submit an enquiry

The full snoMAP Starter map can also be made available as a FHIR ConceptMap which can be syndicated to a conformant FHIR terminology server. If you would like to enquire about this option please email snomap@csiro.au  or submit an enquiry