X00.1XXA ICD-10-CM Code: Exposure to smoke in uncontrolled fire in building or structure, initial encounter

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for X00.1XXA in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on X00.1XXA 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 X00"

• A — initial encounter (this page’s code)
• 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

X00.1XXA, X00.1XXD, X00.1XXS

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 X00.1XXA

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

Before you code X00.1XXA

1. A 7th character is required in this family. Confirm the documented encounter: initial (active treatment), subsequent (healing or recovery phase), or sequela. This page’s code carries “A”. “Initial” means active treatment, not the first visit (Guidelines I.C.19.a).

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

2. 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).

3. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with X00.1XXA. 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 a condition named in X00.1XXA’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.

   ReviewX97

2. Is the underlying (etiologic) condition the Code First note names documented?
   Yes → Sequence the underlying condition first, then X00.1XXA.
   No → Continue; do not add an underlying condition the record does not document.
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 X00.1XXA. 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).

The underlying (etiologic) condition

Named in the Code First note; sequenced before this code when documented (Guidelines I.A.13).

Official instructions as workflow

• Excludes1 — check before selecting X00.1XXA(1 note)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with X00.1XXA: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareX97

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

• Excludes2 — not part of X00.1XXA(6 notes)

  Coding workflow: The conditions named in this note are not included in X00.1XXA. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareX05, X06, X08, T75.0

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

• Code First — sequencing check(1 note)

  Coding workflow: Check whether the underlying or etiologic condition the note names is documented. When it is, sequence it before X00.1XXA. Do not add an underlying condition the record does not document.

  See the official tabular notes · Guidelines I.A.13

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.

Don’t confuse X00.1XXA with…

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

The codes most likely to be picked instead of X00.1XXA — 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.

• X97— Excludes1 conflict (Conflict)

  Not coded here — these two are mutually exclusive.

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

  What moves you there: Documentation of arson moves the case to X97; the two are not reported together unless documented as unrelated.

  Full comparison: X00.1XXA vs X97 →

• X00.1XXD— Encounter relationship (Review)

  Same underlying diagnosis, different encounter phase.

  The same diagnosis at a different phase of care; one encounter takes one 7th character.

  What moves you there: Documentation of a subsequent encounter moves the case to X00.1XXD.

  Full comparison: X00.1XXA vs X00.1XXD →

• X00.1XXS— Encounter relationship (Review)

  Same underlying diagnosis, different encounter phase.

  The same diagnosis at a different phase of care; one encounter takes one 7th character.

  What moves you there: Documentation of a sequela moves the case to X00.1XXS.

  Full comparison: X00.1XXA vs X00.1XXS →

• X05— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of Exposure to ignition or melting of nightwear adds X05; it is not part of this code and both may be reported when both are documented.

  Full comparison: X00.1XXA vs X05 →

• X06— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of Exposure to ignition or melting of other clothing and apparel adds X06; it is not part of this code and both may be reported when both are documented.

  Full comparison: X00.1XXA vs X06 →

• X08— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of Exposure to other specified smoke, fire and flames adds X08; it is not part of this code and both may be reported when both are documented.

  Full comparison: X00.1XXA vs X08 →

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.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

1. A 7th character applies in this family. Confirm the documented encounter matches the character assigned. See the official 7th-character definitions and this code’s variants
2. Sequencing: 1 Code First instruction — the underlying condition is sequenced before this code when present. See the Code First notes
3. 1 Excludes1 entry — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes
4. 6 Excludes2 entries — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

• 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 X00.1XXA 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 12 Excludes1 notes: W13.9 — Fall from, out of or through building, not otherwise specified (via X00.-), X10 — Contact with hot drinks, food, fats and cooking oils (via X00.-), X10-X19 — Contact with heat and hot substances (X10-X19) (via X00.-), X11 — Contact with hot tap-water (via X00.-), X12 — Contact with other hot fluids (via X00.-), X13 — Contact with steam and other hot vapors (via X00.-), X14 — Contact with hot air and other hot gases (via X00.-), X15 — Contact with hot household appliances (via X00.-), X16 — Contact with hot heating appliances, radiators and pipes (via X00.-), X17 — Contact with hot engines, machinery and tools (via X00.-), X18 — Contact with other hot metals (via X00.-), X19 — Contact with other heat and hot substances (via X00.-).

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

Referenced by 22 Excludes2 notes: W00 — Fall due to ice and snow (via X00.-), W00-W19 — Slipping, tripping, stumbling and falls (W00-W19) (via X00.-), W01 — Fall on same level from slipping, tripping and stumbling (via X00.-), W03 — Other fall on same level due to collision with another person (via X00.-), W04 — Fall while being carried or supported by other persons (via X00.-), W05 — Fall from non-moving wheelchair, nonmotorized scooter and motorized mobility scooter (via X00.-), W06 — Fall from bed (via X00.-), W07 — Fall from chair (via X00.-), W08 — Fall from other furniture (via X00.-), W09 — Fall on and from playground equipment (via X00.-), W10 — Fall on and from stairs and steps (via X00.-), W11 — Fall on and from ladder (via X00.-), W12 — Fall on and from scaffolding (via X00.-), W13 — Fall from, out of or through building or structure (via X00.-), W14 — Fall from tree (via X00.-), W15 — Fall from cliff (via X00.-), W16 — Fall, jump or diving into water (via X00.-), W17 — Other fall from one level to another (via X00.-), W18 — Other slipping, tripping and stumbling and falls (via X00.-), W19 — Unspecified fall (via X00.-), +2 more.

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

Referenced by 31 Use Additional Code instructions: T20.0 — Burn of unspecified degree of head, face, and neck (via X00.-), T20.1 — Burn of first degree of head, face, and neck (via X00.-), T20.2 — Burn of second degree of head, face, and neck (via X00.-), T20.3 — Burn of third degree of head, face, and neck (via X00.-), T21.0 — Burn of unspecified degree of trunk (via X00.-), T21.1 — Burn of first degree of trunk (via X00.-), T21.2 — Burn of second degree of trunk (via X00.-), T21.3 — Burn of third degree of trunk (via X00.-), T22.0 — Burn of unspecified degree of shoulder and upper limb, except wrist and hand (via X00.-), T22.1 — Burn of first degree of shoulder and upper limb, except wrist and hand (via X00.-), T22.2 — Burn of second degree of shoulder and upper limb, except wrist and hand (via X00.-), T22.3 — Burn of third degree of shoulder and upper limb, except wrist and hand (via X00.-), T23.0 — Burn of unspecified degree of wrist and hand (via X00.-), T23.1 — Burn of first degree of wrist and hand (via X00.-), T23.2 — Burn of second degree of wrist and hand (via X00.-), T23.3 — Burn of third degree of wrist and hand (via X00.-), T24.0 — Burn of unspecified degree of lower limb, except ankle and foot (via X00.-), T24.1 — Burn of first degree of lower limb, except ankle and foot (via X00.-), T24.2 — Burn of second degree of lower limb, except ankle and foot (via X00.-), T24.3 — Burn of third degree of lower limb, except ankle and foot (via X00.-), +11 more.

These codes instruct coders to additionally report this code when it applies.

Clinical classification (AHRQ CCSR):EXT004 — External cause codes: fire/burn; initial encounter; EXT020 — External cause codes: intent of injury, accidental/unintentional.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (External cause codes: fire/burn; initial encounter, External cause codes: intent of injury, accidental/unintentional).

T54.2X4A — Toxic effect of corrosive acids and acid-like substances, undetermined, initial encounter, T54.3X1A — Toxic effect of corrosive alkalis and alkali-like substances, accidental (unintentional), initial encounter, T54.3X2A — Toxic effect of corrosive alkalis and alkali-like substances, intentional self-harm, initial encounter, T54.3X3A — Toxic effect of corrosive alkalis and alkali-like substances, assault, initial encounter, T54.3X4A — Toxic effect of corrosive alkalis and alkali-like substances, undetermined, initial encounter, T54.91XA — Toxic effect of unspecified corrosive substance, accidental (unintentional), initial encounter, T54.92XA — Toxic effect of unspecified corrosive substance, intentional self-harm, initial encounter, T54.93XA — Toxic effect of unspecified corrosive substance, assault, initial encounter, T54.94XA — Toxic effect of unspecified corrosive substance, undetermined, initial encounter, X00.0XXA — Exposure to flames in uncontrolled fire in building or structure, initial encounter, X00.2XXA — Injury due to collapse of burning building or structure in uncontrolled fire, initial encounter, X00.3XXA — Fall from burning building or structure in uncontrolled fire, initial encounter, X00.4XXA — Hit by object from burning building or structure in uncontrolled fire, initial encounter, X00.5XXA — Jump from burning building or structure in uncontrolled fire, initial encounter, X00.8XXA — Other exposure to uncontrolled fire in building or structure, initial encounter, X01.0XXA — Exposure to flames in uncontrolled fire, not in building or structure, initial encounter, X01.1XXA — Exposure to smoke in uncontrolled fire, not in building or structure, initial encounter, X01.3XXA — Fall due to uncontrolled fire, not in building or structure, initial encounter, X01.4XXA — Hit by object due to uncontrolled fire, not in building or structure, initial encounter, X01.8XXA — Other exposure to uncontrolled fire, not in building or structure, initial encounter, +2335 more

Contextual Map

Every relationship of X00.1XXA 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 X00.1XXA with these 24 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
• X00-X08 — Exposure to smoke, fire and flames[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes (12)

• W13.9 — Fall from, out of or through building, not otherwise specified[Excludes1](via X00.-): “fall or jump from burning building or structure (X00.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X10 — Contact with hot drinks, food, fats and cooking oils[Excludes1](via X00.-): “exposure to fire and flames (X00-X08)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X10-X19 — Contact with heat and hot substances (X10-X19)[Excludes1](via X00.-): “exposure to fire and flames (X00-X08)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X11 — Contact with hot tap-water[Excludes1](via X00.-): “exposure to fire and flames (X00-X08)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X12 — Contact with other hot fluids[Excludes1](via X00.-): “exposure to fire and flames (X00-X08)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X13 — Contact with steam and other hot vapors[Excludes1](via X00.-): “exposure to fire and flames (X00-X08)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X14 — Contact with hot air and other hot gases[Excludes1](via X00.-): “exposure to fire and flames (X00-X08)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• X15 — Contact with hot household appliances[Excludes1](via X00.-): “exposure to fire and flames (X00-X08)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• and 4 more

Referenced by Excludes2 notes (22)

• W00 — Fall due to ice and snow[Excludes2](via X00.-): “fall (in) (from) burning building (X00.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• W00-W19 — Slipping, tripping, stumbling and falls (W00-W19)[Excludes2](via X00.-): “fall (in) (from) burning building (X00.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• W01 — Fall on same level from slipping, tripping and stumbling[Excludes2](via X00.-): “fall (in) (from) burning building (X00.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• W03 — Other fall on same level due to collision with another person[Excludes2](via X00.-): “fall (in) (from) burning building (X00.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• W04 — Fall while being carried or supported by other persons[Excludes2](via X00.-): “fall (in) (from) burning building (X00.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• W05 — Fall from non-moving wheelchair, nonmotorized scooter and motorized mobility scooter[Excludes2](via X00.-): “fall (in) (from) burning building (X00.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• W06 — Fall from bed[Excludes2](via X00.-): “fall (in) (from) burning building (X00.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• W07 — Fall from chair[Excludes2](via X00.-): “fall (in) (from) burning building (X00.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• and 14 more

Referenced by Use Additional Code instructions (31)

• T20.0 — Burn of unspecified degree of head, face, and neck[Use Additional Code](via X00.-): “external cause code to identify the source, place and intent of the burn (X00-X19, X75-X77, X96-X98, Y92)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T20.1 — Burn of first degree of head, face, and neck[Use Additional Code](via X00.-): “external cause code to identify the source, place and intent of the burn (X00-X19, X75-X77, X96-X98, Y92)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T20.2 — Burn of second degree of head, face, and neck[Use Additional Code](via X00.-): “external cause code to identify the source, place and intent of the burn (X00-X19, X75-X77, X96-X98, Y92)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T20.3 — Burn of third degree of head, face, and neck[Use Additional Code](via X00.-): “external cause code to identify the source, place and intent of the burn (X00-X19, X75-X77, X96-X98, Y92)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T21.0 — Burn of unspecified degree of trunk[Use Additional Code](via X00.-): “external cause code to identify the source, place and intent of the burn (X00-X19, X75-X77, X96-X98, Y92)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T21.1 — Burn of first degree of trunk[Use Additional Code](via X00.-): “external cause code to identify the source, place and intent of the burn (X00-X19, X75-X77, X96-X98, Y92)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T21.2 — Burn of second degree of trunk[Use Additional Code](via X00.-): “external cause code to identify the source, place and intent of the burn (X00-X19, X75-X77, X96-X98, Y92)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T21.3 — Burn of third degree of trunk[Use Additional Code](via X00.-): “external cause code to identify the source, place and intent of the burn (X00-X19, X75-X77, X96-X98, Y92)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• and 23 more

Clinical classification (CCSR)

• EXT004 — External cause codes: fire/burn; initial encounter[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)
• EXT020 — External cause codes: intent of injury, accidental/unintentional[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

Nearest codes (28)

• X00 — Exposure to uncontrolled fire in building or structure[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• X00.0 — Exposure to flames in uncontrolled fire in building or structure[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• X00.0XXA — Exposure to flames in uncontrolled fire in building or structure, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• X00.0XXD — Exposure to flames in uncontrolled fire in building or structure, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• X00.0XXS — Exposure to flames in uncontrolled fire in building or structure, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• X00.1 — Exposure to smoke in uncontrolled fire in building or structure[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• X00.1XXD — Exposure to smoke in uncontrolled fire in building or structure, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• X00.1XXS — Exposure to smoke in uncontrolled fire in building or structure, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 20 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 X00.1XXA in its code family, with their registry titles.

• X00.0 — Exposure to flames in uncontrolled fire in building or structure
• X00.0XXA — Exposure to flames in uncontrolled fire in building or structure, initial encounter
• X00.0XXD — Exposure to flames in uncontrolled fire in building or structure, subsequent encounter
• X00.0XXS — Exposure to flames in uncontrolled fire in building or structure, sequela
• X00.1 — Exposure to smoke in uncontrolled fire in building or structure
• X00.1XXD — Exposure to smoke in uncontrolled fire in building or structure, subsequent encounter
• X00.1XXS — Exposure to smoke in uncontrolled fire in building or structure, sequela
• X00.2 — Injury due to collapse of burning building or structure in uncontrolled fire
• X00.2XXA — Injury due to collapse of burning building or structure in uncontrolled fire, initial encounter
• X00.2XXD — Injury due to collapse of burning building or structure in uncontrolled fire, subsequent encounter

View all codes in the X00 family