J70.3 vs J84.9

J70.3 (Chronic drug-induced interstitial lung disorders) compared with J84.9 (Interstitial pulmonary disease, unspecified), from the official CMS tabular data.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources

Summary

These codes should not be reported together because J70.3’s tabular entry lists J84.9 under Excludes1.

Official rule

What is different?

The conditions named.J70.3 is “Chronic drug-induced interstitial lung disorders”; J84.9 is “Interstitial pulmonary disease, unspecified”.

Registry fact

Can these codes be reported together?

No.J70.3’s entry carries an Excludes1 note covering J84.9: “interstitial pneumonia NOS (J84.9)”. 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.J70.3’s tabular entry: “interstitial pneumonia NOS (J84.9)”. The note covers J84.9.

Official ruleGuide: Excludes1 vs Excludes2

Is there an Excludes2 relationship?

Yes.J84.9’s tabular entry: “lung diseases due to external agents (J60-J70)”. The note covers J70.3.

Official ruleGuide: Excludes1 vs Excludes2

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?

No.Both are billable codes, and neither contains the other.

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?

Excludes1 — generally not reported together

Excludes1 conflict

J70.3

Chronic drug-induced interstitial lung disorders

↔

J84.9

Interstitial pulmonary disease, unspecified

What we found

No — do not report together.J70.3 carries an Excludes1 note covering J84.9: “interstitial pneumonia NOS (J84.9)”

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 are not ordinarily reported together for the same encounter, because the classification treats them as mutually exclusive forms of the same condition. The documented exception is when the two conditions are unrelated to each other.

Source / rule

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

Informational

Excludes2 relationship

J84.9

Interstitial pulmonary disease, unspecified

↔

J70.3

Chronic drug-induced interstitial lung disorders

What we found

Yes, when both are documented.J84.9 carries an Excludes2 note covering J70.3: “lung diseases due to external agents (J60-J70)”

Excludes2 marks distinct conditions — both may be reported when both are documented.

What to review

Report both only when the documentation supports both conditions; otherwise report the one documented.

Guide: Excludes1 vs Excludes2 Check these on a claim

Why it matters

An Excludes2 note means the excluded condition is not part of the code above it, but a patient can have both. Report both when both are documented.

Source / rule

CMS ICD-10-CM tabular instructional notes

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 FY2027
Section I.A.12.b — Excludes2 · applies to: Excludes2
A type 2 Excludes note represents “Not included here.” An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
ICD-10-CM Official Guidelines FY2027

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

	J70.3Chronic drug-induced interstitial lung disorders	J84.9Interstitial pulmonary disease, unspecified
Billing status	Billable	Billable
Classification	J00-J99 — Diseases of the Respiratory System (J00-J99)	J00-J99 — Diseases of the Respiratory System (J00-J99)
Definition	Chronic drug-induced interstitial lung disorders is a billable ICD-10-CM diagnosis code (J70.3).	Interstitial pulmonary disease, unspecified is a billable ICD-10-CM diagnosis code (J84.9).
Includes	—	Interstitial pneumonia NOS
Excludes1	interstitial pneumonia NOS (J84.9) lymphoid interstitial pneumonia (J84.2)	drug-induced interstitial lung disorders (J70.2-J70.4) interstitial emphysema (J98.2)
Excludes2	asthma (J45.-) malignant neoplasm of bronchus and lung (C34.-)	lung diseases due to external agents (J60-J70)
Use additional code	code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)	—
Code also	—	, if applicable, associated condition

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.

Editorial explanation — not an official CMS/CDC rule. Official coding instructions and source material are identified below. How to read the labels

The distinction

J70.3 names the cause — chronic interstitial lung disease due to a drug — and J84.9 names the absence of one: interstitial pulmonary disease of unspecified type, whose inclusion term is “Interstitial pneumonia NOS.” The record either attributes the interstitial disease to a drug or it does not, and the classification will not let both statements stand at once.

The deciding question

Does the provider attribute the interstitial lung disease to a drug?

If yes, the J70.2–J70.4 subcategory applies — J70.3 when documented as chronic, J70.2 acute, J70.4 unspecified — and J84.9 is excluded from its side by an Excludes1 for “interstitial pneumonia NOS (J84.9).” J70.3 then asks, by Use Additional Code note, for the drug’s adverse-effect code: a T36–T50 code with fifth or sixth character 5. If the record names no cause, J84.9 stands alone, and J84’s own Excludes1 for “drug-induced interstitial lung disorders (J70.2–J70.4)” keeps the J70 codes off the claim. Neither code is a fallback for the other; the answer changes only when the documentation of cause changes.

Worked examples

Landing on J70.3

Pulmonology documents chronic interstitial lung disease attributed to a long-term medication that was correctly prescribed and taken as directed.

J70.3 — Chronic drug-induced interstitial lung disorders (first)
T36–T50 (…5) — Adverse effect of the documented drug, fifth or sixth character 5, with the encounter’s 7th character (secondary — J70.3’s Use Additional Code note)

J84.9 is not added: J70.3 carries an Excludes1 for interstitial pneumonia NOS (J84.9). The adverse-effect code is the T36–T50 column that follows the reaction it caused, exactly as the poisoning-vs-adverse-effect guide describes.

Landing on J84.9

Imaging and the note document interstitial pulmonary disease; the type is not specified and no cause is attributed.

J84.9 — Interstitial pulmonary disease, unspecified (sole code)

No J70 code applies without a documented drug cause, and J84’s Excludes1 for J70.2–J70.4 bars adding one on suspicion. If a specific other interstitial type is later documented, the code moves within J84.- rather than to J70.

Why coders confuse them

Both codes describe interstitial lung disease, so a chart with a drug on the medication list and an interstitial pattern on imaging invites coding both — one for the disease, one for the drug. The classification treats them as alternatives: J70.3 is already the interstitial disease, with its cause built in, and the drug is identified by the T-code J70.3 asks for, not by J84.9.

Claim Check reports this pair under both note types because J84 carries two notes pointing at the J70 family: a specific Excludes1 for drug-induced interstitial lung disorders (J70.2–J70.4), and a broad Excludes2 for the whole J60–J70 block of lung diseases due to external agents. The Excludes2 is real — other J60–J70 conditions can coexist with a J84 code — but for this pair the specific Excludes1 is the one that governs, and J70.3 confirms it from its own side.

FAQ

Can J70.3 and J84.9 be reported together?

No. J70.3 carries an Excludes1 for interstitial pneumonia NOS (J84.9), and category J84 carries an Excludes1 for drug-induced interstitial lung disorders (J70.2–J70.4). The two describe the same interstitial disease with and without a documented drug cause, and only one can be true of a record.

Which additional code does J70.3 require?

The adverse-effect code for the drug: J70.3’s Use Additional Code note asks for a T36–T50 code with fifth or sixth character 5, if applicable, to identify the drug. That is the adverse-effect column — the drug was correctly prescribed and properly administered — so it is sequenced after J70.3, the reaction it caused.

Why does Claim Check flag this pair as both Excludes1 and Excludes2?

Because category J84 carries both: an Excludes1 naming the drug-induced codes J70.2–J70.4 specifically, and an Excludes2 for the broader J60–J70 block. The specific Excludes1 governs this pair. The Excludes2 exists for the other external-agent conditions in J60–J70 that a patient may genuinely have alongside a J84 code.

Excludes1 vs Excludes2: when two codes can be reported together·Poisoning, adverse effect, or underdosing: which T36–T50 column·J70.4 — Drug-induced interstitial lung disorders, unspecified

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Derived from the official CMS ICD-10-CM tabular data (FY2027). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources