X08.8XXS vs X97

X08.8XXS (Exposure to other specified smoke, fire and flames, sequela) compared with X97 (Assault by smoke, fire and flames), from the official CMS tabular data.

Summary

These codes should not be reported together because X08.8XXS’s tabular entry lists X97 under Excludes1.

Official rule

What is different?

The conditions named and billing status.X08.8XXS is “Exposure to other specified smoke, fire and flames, sequela”; X97 is “Assault by smoke, fire and flames”. X97 is a non-billable header; X08.8XXS is billable.

Registry fact

Can these codes be reported together?

No.X08.8XXS’s entry carries an Excludes1 note covering X97: “arson (X97)”. Both may be reported only when the documentation shows the two conditions are unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Official ruleGuide: Excludes1 vs Excludes2

Is there an Excludes1 relationship?

Yes.X08.8XXS’s tabular entry: “arson (X97)”. The note covers X97.

Official ruleGuide: Excludes1 vs Excludes2

Is there an Excludes2 relationship?

None.Neither entry carries an Excludes2 note that names the other code. X08.8XXS carries 3 Excludes2 notes covering other codes; the side-by-side table quotes them.

Official rule

Is one more specific?

Not comparable.The codes sit in different categories; specificity is only comparable within one category.

Is one a parent or header code?

One is a header.X97 is a non-billable header, but X08.8XXS is not one of its subdivisions.

Registry fact

Are there sequencing instructions?

None.Neither entry carries a Code First or Use Additional Code note that names the other.

Official rule

Are there other coding relationships?

None found.No laterality, encounter-phase, Table of Neoplasms, Table of Drugs and Chemicals, or history-versus-active-disease relationship links these codes.

MedCoder-derived

Official rule: a tabular instructional note or a section of the ICD-10-CM Official Guidelines, quoted as published. Registry fact: the codes’ own published attributes (titles, billable status, position in the hierarchy, code set). MedCoder-derived: a reading MedCoder computes from those facts; it is not itself a rule. How to read the labels

Can these codes be reported together?

Conflict

Excludes1 conflict

X08.8XXS

Exposure to other specified smoke, fire and flames, sequela

↔

X97

Assault by smoke, fire and flames

What we found

No — do not report together.X08.8XXS carries an Excludes1 note covering X97: “arson (X97)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

What to review

Report one of the two. Both may be reported only when the documentation shows the two conditions are unrelated to each other.

Guide: Excludes1 vs Excludes2 Check these on a claim

Why it matters

An Excludes1 note means the two conditions cannot occur together, so the pair should not be reported for the same encounter. The sole exception is when the conditions are documented as unrelated to each other.

Source / rule

CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a

Official guidance behind these answers

Section I.A.12.a — Excludes1 · applies to: Excludes1
A type 1 Excludes note is a pure excludes note. It means “NOT CODED HERE!” An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition. An exception to the Excludes1 definition is the circumstance when the two conditions are unrelated to each other. If it is not clear whether the two conditions involving an Excludes1 note are related or not, query the provider. For example, code F45.8, Other somatoform disorders, has an Excludes1 note for "sleep related teeth grinding (G47.63)," because "teeth grinding" is an inclusion term under F45.8. Only one of these two codes should be assigned for teeth grinding. However psychogenic dysmenorrhea is also an inclusion term under F45.8, and a patient could have both this condition and sleep related teeth grinding. In this case, the two conditions are clearly unrelated to each other, and so it would be appropriate to report F45.8 and G47.63 together.
ICD-10-CM Official Guidelines FY2026

Quoted from the ICD-10-CM Official Guidelines for Coding and Reporting in effect for the release shown. The tabular notes above are the code-level instruction; these sections are the convention that says how such a note is applied. Source document (CMS PDF) · Release and checksum

Side by side

	X08.8XXSExposure to other specified smoke, fire and flames, sequela	X97Assault by smoke, fire and flames
Billing status	Billable	Non-billable header Report instead: X97.XXXA, X97.XXXD, X97.XXXS
Classification	V00-Y99 — External Causes of Morbidity (V00-Y99)	V00-Y99 — External Causes of Morbidity (V00-Y99)
Definition	Exposure to other specified smoke, fire and flames, sequela is a billable ICD-10-CM diagnosis code (X08.8XXS).	Assault by smoke, fire and flames is a non-billable ICD-10-CM category code (X97).
7th character	The appropriate 7th character is to be added to each code from category X08	The appropriate 7th character is to be added to code X97
Includes	—	homicide injuries inflicted by another person with intent to injure or kill, by any means Assault by arson Assault by cigarettes
Excludes1	arson (X97)	injuries due to legal intervention (Y35.-) injuries due to operations of war (Y36.-) injuries due to terrorism (Y38.-)
Excludes2	explosions (W35-W40) lightning (T75.0-) transport accident (V01-V99)	—

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on.

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Derived from the official CMS ICD-10-CM tabular data (FY2026). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources