ICD-10 Vietnam edition: Decision 4469/QĐ-BYT and the ICD-11 outlook

1. What is ICD-10? A brief history

ICD-10 (International Classification of Diseases, 10th Revision) is the World Health Organization's tenth revision of its disease classification. The World Health Assembly (WHA) adopted ICD-10 in May 1990 and the official code set took effect on 01/01/1993. WHO stopped adding new content to ICD-10 in 2018 and shifted its focus to ICD-11 — the next-generation revision.

The full VN Core ICD-10 VN artifact contains 15,026 codes from the processed source corpus, spanning several levels of detail and national extension branches. ICD-10 supports classification in health records, epidemiological and mortality reporting, and insurance workflows; valid-code scope must follow the applicable catalog version.

In Vietnam, ICD-10 has been in use since the early 2000s under several different translations. In 2020, the Ministry of Health consolidated these into a single official edition through Decision 4469/QĐ-BYT, taking ICD-10 WHO 2019 as its baseline, translating it into Vietnamese, and adding detailed branches for diseases of epidemiological significance in Vietnam.

2. Code structure: chapter, block, category, sub-category

ICD-10 is organized into four classification levels. At the top sit chapters — 22 broad disease groups numbered with Roman numerals. Each chapter contains multiple blocks, contiguous ranges of three-character codes. Each block holds three-character categories, and each category may be split into four-character sub-categories after the decimal point.

Chapter (I-XXII)        e.g., Chapter IX — Diseases of the circulatory system
   └── Block             e.g., I00-I99
       └── Category      e.g., I10 (3 characters)
           └── Sub-category   e.g., I10.0 (4 characters)
               └── VN extension   e.g., I10.00 (5 characters — only in ICD-10 VN)

A few common examples: I10 is essential hypertension, J00-J06 is the block for acute upper respiratory infections, and E11.9 is type 2 diabetes mellitus without complications. Five-character branches such as I10.00 are extensions added by ICD-10 VN for selected diseases and do not exist in standard ICD-10 WHO.

3. Where ICD-10 VN diverges from ICD-10 WHO

ICD-10 VN is derived from ICD-10 WHO, but that does not make every code, display, or extension branch automatically equivalent across versions. Exchange requires both sides to identify the edition/version and use a tested comparison table or ConceptMap; the following are the principal differences.

First, Vietnamese descriptions in the national catalog. Vietnamese displays support EMR software and BHYT forms; an English display from the source version may be retained as a designation where source and licensing permit. A display is not a code identifier and does not prove semantic equivalence.

Second, five-character branch extensions for diseases common in Vietnam. Typical examples include dengue hemorrhagic fever (codes A90 and A91 are subdivided by clinical severity) and viral hepatitis B (B16 and B18 are subdivided by chronic, acute, or co-infection status). These are diseases with a high epidemiological burden in Vietnam that need finer resolution than ICD-10 WHO provides by default.

Third, epidemiology-driven supplements. Decision 98/QĐ-BYT (14/01/2022) added U07.1 and U07.2 for COVID-19. WHO had actually published these codes back in April 2020 through ICD-10 mid-cycle updates, but Vietnam formally adopted them through legal instrument only in early 2022. Clinical commentary accompanying the code set is reviewed and refreshed periodically by the Ministry of Health through separate guidance documents.

4. Decision 4469/QĐ-BYT — the founding document

Decision 4469/QĐ-BYT was signed by the Minister of Health on 28/10/2020. It promulgated both the "International Classification of Diseases and Causes of Death (ICD-10)" and the "International Classification of Surgeries and Procedures (ICD-9-CM)" for use across all healthcare facilities nationwide. The ICD-10 portion is the original ICD-10 VN edition referenced throughout this document.

The Ministry of Health published two annexes alongside the decision: an Excel code catalog (with columns for Code, Vietnamese description, English description, and Notes) and a printed PDF of the full classification. The decision does not assign a SemVer-style version number, so VN Core combines the signing date with the document code (QD-4469-2020) to identify the version inside the CodeSystem.

According to the VN Core legal registry (reviewed 13/07/2026), Decision 4469 remains the foundation document for ICD-10 VN. In addition, Circular 06/2026/TT-BYT on ICD-10 coding (issued 02/04/2026) has been in force since 01/07/2026 — it specifies the principles for selecting primary and secondary codes and the quality assurance process for coding. VN Core lists TT-06-2026 in VNLegalDocumentRefCS with status in-force; ICD-10 coding Must Support constraints follow this current document.

5. Decision 98/QĐ-BYT — COVID-19 codes

Decision 98/QĐ-BYT, dated 14/01/2022, added two codes to ICD-10 VN for SARS-CoV-2 disease. It was Vietnam's legal response to WHO's mid-cycle update during the pandemic.

• U07.1 — COVID-19, virus identified. Used when laboratory testing confirms the virus (a positive RT-PCR result or another confirmatory assay). This was the dominant code during 2022-2023 when PCR testing was widely available.
• U07.2 — COVID-19, virus not identified. Used when diagnosis rests on clinical signs and epidemiological factors, with no virological confirmation available — or none possible. This code typically appears during major outbreaks when testing capacity is overwhelmed.

In FHIR, both codes live within the same ICD-10 VN CodeSystem; no separate CodeSystem is needed. When coding a COVID-19 case, U07.1 or U07.2 occupies the primary code position. Codes for complications (COVID-19 pneumonia, post-COVID syndrome, and so on) use ordinary ICD-10 codes in secondary positions. Distinguishing U07.1 from U07.2 matters for both epidemiological statistics and BHYT settlement, since reimbursement policy may differ between the two groups.

6. ICD-9-CM Volume 3 — surgical and procedural coding

ICD-10 only classifies diagnoses; it does not code procedures. To code surgeries and procedures, the Vietnamese health sector continues to use ICD-9-CM Volume 3 (International Classification of Diseases, 9th Revision, Clinical Modification, Volume 3) — a procedure code set developed in the United States on the legacy ICD-9 base. Although the United States migrated to ICD-10-PCS in 2015, Vietnam retains ICD-9-CM Volume 3 because it is deeply embedded in the existing technical service catalog (DVKT) and DRG grouping algorithms.

Decision 387/QĐ-BYT, dated 05/02/2026, issued the 2026 edition of "International Classification of Surgeries and Procedures (ICD-9-CM)", replacing Decision 4440/QĐ-BYT (27/10/2020). Its scope covers surgical procedures, diagnostic and interventional imaging procedures, and nursing procedures. Terminology loaders should derive the code count and content directly from the official 2026 annex rather than reusing an estimate from an earlier edition.

FHIR use cases include populating Procedure.code, mapping to the Ministry of Health technical service (DVKT) catalog for BHYT reimbursement, and feeding the diagnosis-related group (DRG) algorithm. VN Core registers this CodeSystem at the canonical URL http://fhir.hl7.org.vn/core/CodeSystem/vn-icd9-cm-cs (note the hyphen between icd9 and cm, plus the -cs suffix per VN Core naming conventions).

7. ICD-11 — Vietnam status and transition requirements

The 72nd World Health Assembly adopted ICD-11 in 2019, and it came into effect on 1 January 2022. ICD-11 is designed for digital use and supports post-coordination — combining codes into clinically meaningful clusters — so transition affects policy, software, data, and coding workforce capabilities.

WHO implementation guidance states that countries may continue using ICD-10 for as long as necessary and recommends planned transition work including readiness assessment, pilots, training, and continuity of historical data. Each country's status should be checked against current WHO and national-authority sources; this page does not infer regional status from aggregate figures or assign a status to individual countries without current primary evidence.

In Vietnam, the VN Core legal registry reviewed in June 2026 does not yet include a legal instrument or formal program for ICD-11 adoption. The current implementation priority is stabilizing ICD-10 VN during the rollout of electronic medical records (Circular 13/2025/TT-BYT) and BHYT data interoperability under Decision 3176/QĐ-BYT. Any future ICD-11 transition would need versioned terminology services, tested ICD-10 ⇄ ICD-11 ConceptMaps, workforce retraining, and a pilot phase with a clearly published scope.

8. FHIR integration — canonical URIs and a Condition example

Canonical URIs (per the VNCoreConditionDiagnosis FSH)

Purpose	URI
Coding.system in Condition.code (per the VNCoreConditionDiagnosis profile)	http://hl7.org/fhir/sid/icd-10
ICD-10 VN ValueSet binding	http://fhir.hl7.org.vn/core/ValueSet/vn-icd10-vs
VN ICD-10 CodeSystem metadata wrapper	http://fhir.hl7.org.vn/core/CodeSystem/vn-icd10-cs
ICD-9-CM VN CodeSystem	http://fhir.hl7.org.vn/core/CodeSystem/vn-icd9-cm-cs
SNOMED CT (international)	http://snomed.info/sct

VNCoreConditionDiagnosis uses the HL7 URI http://hl7.org/fhir/sid/icd-10 as the coding namespace, while vn-icd10-vs defines the codes accepted by the profile. This supports namespace recognition but does not guarantee interoperability: sender and receiver must still agree on Coding.version, ValueSet scope, and handling of Vietnamese extension branches. vn-icd10-cs is a metadata/download surface for Vietnamese displays and properties, not the Coding.system used in instances.

A Condition example following VNCoreConditionDiagnosis

{
  "resourceType": "Condition",
  "subject": {"reference": "Patient/vn-001"},
  "encounter": {"reference": "Encounter/enc-001"},
  "code": {
    "coding": [
      {
        "system": "http://hl7.org/fhir/sid/icd-10",
        "version": "QD-4469-2020",
        "code": "I10.0",
        "display": "Tăng huyết áp vô căn"
      },
      {
        "system": "http://snomed.info/sct",
        "code": "38341003",
        "display": "Hypertensive disorder"
      }
    ],
    "text": "Tăng huyết áp"
  },
  "clinicalStatus": {
    "coding": [{
      "system": "http://terminology.hl7.org/CodeSystem/condition-clinical",
      "code": "active"
    }]
  },
  "verificationStatus": {
    "coding": [{
      "system": "http://terminology.hl7.org/CodeSystem/condition-ver-status",
      "code": "confirmed"
    }]
  }
}

The clinicalStatus and verificationStatus fields must use the exact URIs of the standard HL7 CodeSystems — http://terminology.hl7.org/CodeSystem/condition-clinical for active and http://terminology.hl7.org/CodeSystem/condition-ver-status for confirmed. FHIR R4 binds both with required strength; placeholder URIs will fail validation.

9. Mapping design for ICD-10 VN, ICD-10 WHO, and SNOMED CT

VN Core v0.9.0 already includes a draft ConceptMap from ICD-10 VN to SNOMED CT, plus related ConceptMaps for CLS-to-LOINC, BHYT financial fields to adjudication, and legacy-to-new province mapping. The layers below should be read as a design stack, not as three fully completed artifacts in the same release.

• vn-icd10-to-icd10-who — maps the five-character VN extension codes back to their corresponding four-character ICD-10 WHO codes. This ConceptMap is needed when Vietnamese data is sent to international systems (WHO epidemiological reporting, multi-country research).
• vn-cm-icd10-to-snomed — the current draft artifact selectively maps 143 ICD-10 VN source codes to SNOMED CT. Relationship is stated per element; this one-way artifact implies neither a reverse map nor equivalence outside its scope.
• xml4210-to-fhir-condition — a design layer for mapping an XML diagnosis field to a Condition carrying ICD-10 VN. It does not replace the current XML channel; an implementation must define source/target versions, error handling, and integration tests against the BHXH workflow.

The ConceptMaps in VN Core v0.9.0 remain draft artifacts and should be piloted with real hospital data before they are treated as mandatory conformance. Decision 2427/QĐ-BYT (SNOMED CT VN Batch 1, Body Structure) and batches 2-3 are the primary source data for the SNOMED CT mapping.

Every dual-coding flow must declare source and target systems and versions, scope, mapping direction, and the per-element R4 ConceptMap equivalence. Never assume two codes are equivalent: test common codes, extension branches, one-to-many and unmapped cases, and round-trip behavior before using a map for reporting, clinical decisions, or reimbursement.

10. FAQ

Can ICD-10 WHO be used instead of ICD-10 VN?

This cannot be answered from the code string alone. Check the profile, legal workflow, and catalog version required by the receiver; a Vietnamese extension branch may not exist in the target WHO edition. Send dual coding only after declaring system/version, mapping direction and relationship in a ConceptMap, and testing the map with representative data. Two entries in one CodeableConcept do not by themselves prove equivalence.

ICD-11 is coming — should we wait?

No, not if your project is implementing EMR or BHYT workflows now. The VN Core legal registry reviewed in June 2026 does not yet include an ICD-11 roadmap for Vietnam. The safer approach is to implement ICD-10 VN properly today while designing your terminology server with versioning and ConceptMaps so a future official transition remains possible.

Do we need to install ICD-10 VN into our database?

Yes. To support lookup, autocomplete, and validation inside EMR software, the full ICD-10 VN CodeSystem needs to be loaded into a FHIR terminology server or an application database lookup table. HAPI FHIR JPA Server can load the CodeSystem JSON and serve $lookup and $validate-code directly.

Does Decision 4469 ship with an Excel file?

Yes. The Ministry of Health published an Excel code catalog alongside Decision 4469, downloadable from the Ministry of Health portal or various online legal libraries. The Excel file is the source of truth for building the FHIR CodeSystem.

How long will the COVID-19 codes U07.1 and U07.2 stay in use?

Both codes remain in force and will continue to be used for every COVID-19 case, regardless of pandemic status. WHO has set no expiration for them.

11. References and further reading

Vietnamese legal documents

• Decision 4469/QĐ-BYT (28/10/2020) — Vietnam edition of the ICD-10 international classification of diseases and ICD-9-CM. VN Core document code: QD-4469-2020.
• Decision 98/QĐ-BYT (14/01/2022) — Adds COVID-19 codes (U07.1, U07.2) to ICD-10 VN. Document code: QD-98-2022.
• Decision 387/QĐ-BYT (05/02/2026) — 2026 edition of the ICD-9-CM international classification of surgeries and procedures, replacing Decision 4440/QĐ-BYT. Document code: QD-387-2026.
• Circular 06/2026/TT-BYT (issued 02/04/2026, in force since 01/07/2026) — Regulates ICD-10 coding. Document code: TT-06-2026. Status: in-force.
• Full lookup at the VN Core Legal Corpus page.

International references

• WHO — Classification of Diseases (ICD-10 and ICD-11 history).
• WHO — WHA72 adoption of ICD-11 (adopted in 2019, effective 1 January 2022).
• WHO — ICD-11 implementation FAQ (transition principles and planning).
• ICD-10 WHO 2019 Browser — the upstream baseline for ICD-10 VN.
• FHIR R4 — Condition Resource (definition of clinicalStatus, verificationStatus, and binding constraints).
• HL7 FHIR — ICD-10 Code System (URI http://hl7.org/fhir/sid/icd-10).
• SNOMED International — SNOMED CT for cross-mapping.

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