W40.8 ICD-10-CM Code: Explosion of other specified explosive materials

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for W40.8 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on W40.8 itself; “inherited from” names the category or block whose note applies here.

7th Character Guide

"The appropriate 7th character is to be added to each code from category W40"

• A — initial encounter
• D — subsequent encounter
• S — sequela

How the encounter character is assigned. “Initial encounter” means the patient is receiving active treatment for the condition — it is not limited to the first visit, and a different or new provider giving active treatment still assigns it. “Subsequent encounter” covers care during the healing or recovery phase after active treatment. “Sequela” is for complications or conditions that arise as a direct result of the original condition.

ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19.a (paraphrased by MedCoder).

Variant codes in this family

W40.8XXA, W40.8XXD, W40.8XXS

Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.

Coder workflow for W40.8

MedCoder structured workflow — derived from this code’s own official record

Before you code W40.8

1. W40.8 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

   ReviewW40.8XXA, W40.8XXD, W40.8XXS

   See the relationships section · Guide: How to choose an ICD-10-CM code →

2. “Other” (NEC) means the condition is specified in the record but no dedicated code captures it. Confirm the documented form is not one a sibling code names before settling on W40.8; if the record states no specifics at all, the unspecified sibling applies instead. “Other” codes are for documented conditions the classification gives no specific code; “unspecified” codes are for records lacking the detail (Guidelines I.A.9.a, I.A.9.b).

   ReviewW40.0, W40.1

   See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

3. A 7th character is required in this family. Confirm the documented encounter: initial (active treatment), subsequent (healing or recovery phase), or sequela. W40.8 is not valid without one. “Initial” means active treatment, not the first visit (Guidelines I.C.19.a).

   See the 7th Character Guide · Guide: 7th characters: initial, subsequent, sequela →

4. An external cause code is reported in addition to the code for the injury or condition, never as the principal or first-listed diagnosis. Confirm the cause, intent, place of occurrence, activity and status where the record documents them, and assign the 7th character that matches the injury code. External cause coding guidelines (Guidelines I.C.20.a).

5. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with W40.8. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

   See the official tabular notes

Choose the right path

1. Does the documentation support one of the more specific codes beneath W40.8?
   Yes → Select that code and continue the checks below on its own page.
   No → W40.8 cannot be reported as written; query for the specificity its subcategory needs.

   ReviewW40.8XXA, W40.8XXD, W40.8XXS

2. Does the documentation support a condition named in W40.8’s Excludes1 note?
   Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
   No → Continue.

   ReviewY35.1, Y36.0, Y36.2, X96, X75, Y36

3. Is the encounter phase documented — active treatment, healing or recovery, or a sequela?
   Yes → Assign the matching 7th character; the variant codes are in the 7th Character Guide.
   No → The code is invalid without its 7th character — query for the missing element.

Consider W40.8. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement

Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

Encounter type

Active treatment, healing or recovery phase, or sequela — the basis of the 7th character (Guidelines I.C.19.a).

Any detail beyond this code’s title

What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

• Excludes1 — check before selecting W40.8(8 notes)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with W40.8: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareY35.1, Y36.0, Y36.2, X96, X75, Y36

  See the official tabular notes · Guidelines I.A.12.a

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Indexed As (16)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Circumstance phrases from the official ICD-10-CM External Cause of Injuries Index that map to this code.

• Explosion (accidental) (of) (with secondary fire), antipersonnel bomb
• Explosion (accidental) (of) (with secondary fire), dump (munitions)
• Explosion (accidental) (of) (with secondary fire), explosive (material), specified NEC
• Explosion (accidental) (of) (with secondary fire), factory (munitions)
• Explosion (accidental) (of) (with secondary fire), fertilizer bomb
• Explosion (accidental) (of) (with secondary fire), gasolinenot in moving motor vehicle (fumes) (tank), bomb
• Explosion (accidental) (of) (with secondary fire), grain store
• Explosion (accidental) (of) (with secondary fire), grenade
• Explosion (accidental) (of) (with secondary fire), in, on, dump
• Explosion (accidental) (of) (with secondary fire), in, on, factory
• Explosion (accidental) (of) (with secondary fire), letter bomb
• Explosion (accidental) (of) (with secondary fire), missile NEC
• Explosion (accidental) (of) (with secondary fire), mortar bomb
• Explosion (accidental) (of) (with secondary fire), munitions (dump) (factory)
• Explosion (accidental) (of) (with secondary fire), pipe, pressurized, bomb
• Explosion (accidental) (of) (with secondary fire), shell NEC (artillery)

Don’t confuse W40.8 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of W40.8 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• Y35.1— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of explosion involving legal intervention moves the case to Y35.1; the two are not reported together unless documented as unrelated.

  Full comparison: W40.8 vs Y35.1 →

• Y36.0— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of explosion involving military or war operations moves the case to Y36.0; the two are not reported together unless documented as unrelated.

  Full comparison: W40.8 vs Y36.0 →

• Y36.2— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of explosion involving military or war operations moves the case to Y36.2; the two are not reported together unless documented as unrelated.

  Full comparison: W40.8 vs Y36.2 →

• X96— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of assault by explosive material moves the case to X96; the two are not reported together unless documented as unrelated.

  Full comparison: W40.8 vs X96 →

• X75— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of intentional self-harm by explosive material moves the case to X75; the two are not reported together unless documented as unrelated.

  Full comparison: W40.8 vs X75 →

• X92— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of assault moves the case to X92; the two are not reported together unless documented as unrelated.

  Full comparison: W40.8 vs X92 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Verify Before Coding

• Not billable as written — a more specific code is required: W40.8XXA, W40.8XXD, W40.8XXS.
• Requires a 7th character. "The appropriate 7th character is to be added to each code from category W40" Options: W40.8XXA, W40.8XXD, W40.8XXS
• Principal-diagnosis restriction. External cause of morbidity codes (V, W, X and Y) describe the circumstance that caused an injury, not the condition treated. The Medicare Code Editor rejects them as a principal diagnosis; sequence the injury or condition first and report this code as secondary.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name W40.8 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 2 Excludes1 notes: W20 — Struck by thrown, projected or falling object (via W40.-), W30 — Contact with agricultural machinery.

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 9 Excludes2 notes: X00 — Exposure to uncontrolled fire in building or structure (via W40.-), X00-X08 — Exposure to smoke, fire and flames (X00-X08) (via W40.-), X01 — Exposure to uncontrolled fire, not in building or structure (via W40.-), X02 — Exposure to controlled fire in building or structure (via W40.-), X03 — Exposure to controlled fire, not in building or structure (via W40.-), X04 — Exposure to ignition of highly flammable material (via W40.-), X05 — Exposure to ignition or melting of nightwear (via W40.-), X06 — Exposure to ignition or melting of other clothing and apparel (via W40.-), X08 — Exposure to other specified smoke, fire and flames (via W40.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Referenced by 1 Code First instruction: W25 — Contact with sharp glass (via W40.-).

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

Contextual Map

Every relationship of W40.8 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run W40.8 with these 11 related codes in Claim Check

Hierarchy

• V00-Y99 — Chapter 20: External Causes of Morbidity (V00-Y99) (V00-Y99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• W00-X58 — Other external causes of accidental injury[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• W20-W49 — Exposure to inanimate mechanical forces[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• W20 — Struck by thrown, projected or falling object[Excludes1](via W40.-): “object set in motion by explosion (W35-W40)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• W30 — Contact with agricultural machinery[Excludes1]: “explosion of grain store (W40.8)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes2 notes (9)

• X00 — Exposure to uncontrolled fire in building or structure[Excludes2](via W40.-): “explosions (W35-W40)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X00-X08 — Exposure to smoke, fire and flames (X00-X08)[Excludes2](via W40.-): “explosions (W35-W40)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X01 — Exposure to uncontrolled fire, not in building or structure[Excludes2](via W40.-): “explosions (W35-W40)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X02 — Exposure to controlled fire in building or structure[Excludes2](via W40.-): “explosions (W35-W40)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X03 — Exposure to controlled fire, not in building or structure[Excludes2](via W40.-): “explosions (W35-W40)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X04 — Exposure to ignition of highly flammable material[Excludes2](via W40.-): “explosions (W35-W40)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X05 — Exposure to ignition or melting of nightwear[Excludes2](via W40.-): “explosions (W35-W40)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X06 — Exposure to ignition or melting of other clothing and apparel[Excludes2](via W40.-): “explosions (W35-W40)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• and 1 more

Referenced by Code First instructions

• W25 — Contact with sharp glass[Code First](via W40.-): “injury due to flying glass from explosion or firearm discharge (W32-W40)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

External cause index (16)

• Explosion (accidental) (of) (with secondary fire), antipersonnel bomb[External cause term]— CMS External Cause of Injuries Index · icd10cm-fy2026
• Explosion (accidental) (of) (with secondary fire), dump (munitions)[External cause term]— CMS External Cause of Injuries Index · icd10cm-fy2026
• Explosion (accidental) (of) (with secondary fire), explosive (material), specified NEC[External cause term]— CMS External Cause of Injuries Index · icd10cm-fy2026
• Explosion (accidental) (of) (with secondary fire), factory (munitions)[External cause term]— CMS External Cause of Injuries Index · icd10cm-fy2026
• Explosion (accidental) (of) (with secondary fire), fertilizer bomb[External cause term]— CMS External Cause of Injuries Index · icd10cm-fy2026
• Explosion (accidental) (of) (with secondary fire), gasolinenot in moving motor vehicle (fumes) (tank), bomb[External cause term]— CMS External Cause of Injuries Index · icd10cm-fy2026
• Explosion (accidental) (of) (with secondary fire), grain store[External cause term]— CMS External Cause of Injuries Index · icd10cm-fy2026
• Explosion (accidental) (of) (with secondary fire), grenade[External cause term]— CMS External Cause of Injuries Index · icd10cm-fy2026
• and 8 more

Nearest codes (16)

• W40 — Explosion of other materials[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• W40.0 — Explosion of blasting material[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• W40.0XXA — Explosion of blasting material, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• W40.0XXD — Explosion of blasting material, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• W40.0XXS — Explosion of blasting material, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• W40.1 — Explosion of explosive gases[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• W40.1XXA — Explosion of explosive gases, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• W40.1XXD — Explosion of explosive gases, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 8 more

Change history

• FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Common coding questions

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data

CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page

Change history and date-of-service validity Official source data

CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page

Comparisons, relationships and the contextual map MedCoder structured relationship

Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears

Summary and FAQ answers MedCoder explanation

Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Nearest Codes in This Family

Official ICD-10-CM classifications closest to W40.8 in its code family, with their registry titles.

• W40.0XXS — Explosion of blasting material, sequela
• W40.1 — Explosion of explosive gases
• W40.1XXA — Explosion of explosive gases, initial encounter
• W40.1XXD — Explosion of explosive gases, subsequent encounter
• W40.1XXS — Explosion of explosive gases, sequela
• W40.8XXA — Explosion of other specified explosive materials, initial encounter
• W40.8XXD — Explosion of other specified explosive materials, subsequent encounter
• W40.8XXS — Explosion of other specified explosive materials, sequela
• W40.9 — Explosion of unspecified explosive materials
• W40.9XXA — Explosion of unspecified explosive materials, initial encounter

View all codes in the W40 family