ICD10
ICD-10 Code J18: Pneumonia, unspecified organism
Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026
What is this code?
ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Diseases of the respiratory system (J00-J99).
When is it used?
- May be used when a clinician documents pneumonia, unspecified organism in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
- This entry may represent a broader category rather than the most specific billable code.
Code hierarchy
chapter
10Diseases of the respiratory system (J00-J99)
block
J09-J18Influenza and pneumonia
currentJ09-J18
Official coding notes
Applicable to
- , if applicable, associated influenza (J09.X1, J10.0-, J11.0-)
Excludes1 (do not code together)
- congenital pneumonia (P23.0)
- drug-induced interstitial lung disorder (J70.2-J70.4)
- interstitial pneumonia NOS (J84.9)
- neonatal aspiration pneumonia (P24.-)
- pneumonitis due to fumes and vapors (J68.0)
- usual interstitial pneumonia (J84.178)
Excludes2 (may code together if documented)
- abscess of lung with pneumonia (J85.1)
- aspiration pneumonia due to anesthesia during labor and delivery (O74.0)
- aspiration pneumonia due to anesthesia during pregnancy (O29)
- aspiration pneumonia due to anesthesia during puerperium (O89.0)
- aspiration pneumonia due to solids and liquids (J69.-)
- aspiration pneumonia NOS (J69.0)
- lipid pneumonia (J69.1)
- pneumonitis due to external agents (J67-J70)
Code first
- , if applicable, associated influenza (J09.X1, J10.0-, J11.0-)
Code also
- , if applicable, any associated condition such as:
- aspiration pneumonia (J69.-)
Where you may see this code
You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.
Related specialists
PulmonologistGeneral Physician
Related codes
Sibling codes
J09Influenza due to certain identified influenza virusesJ10Influenza due to other identified influenza virusJ11Influenza due to unidentified influenza virusJ12Viral pneumonia, not elsewhere classifiedJ13Pneumonia due to Streptococcus pneumoniaebillableJ14Pneumonia due to Hemophilus influenzaebillableJ15Bacterial pneumonia, not elsewhere classifiedJ16Pneumonia due to other infectious organisms, not elsewhere classifiedJ17Pneumonia in diseases classified elsewherebillable
Coding guidelines
Compatibility
Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.
Legacy codes
J18
Replacement codes
J18.0 — Bronchopneumonia, unspecified organismJ18.1 — Lobar pneumonia, unspecified organismJ18.2 — Hypostatic pneumonia, unspecified organismJ18.8 — Other pneumonia, unspecified organismJ18.9 — Pneumonia, unspecified organism
Common synonyms
Pneumonia, unspecified organismPneumonia
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.