J18

ICD-10Non-billable category

Pneumonia, unspecified organism

Official ICD-10-CM descriptor (FY2026)

Pneumonia, unspecified organism

J18 is a category heading, not a billable code. CMS does not accept it on a claim; report one of the more specific codes beneath it.

Excludes1

Not coded here. An Excludes1 code should never be reported at the same time as the code above it.

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

Not included here. The condition is not part of this code, but a patient may have both, and both codes may be reported together.

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

Sequence the underlying condition before this code.

, if applicable, associated influenza (J09.X1, J10.0-, J11.0-)

Code also

Two codes may be needed; sequencing depends on the reason for the encounter.

, if applicable, any associated condition such as:
aspiration pneumonia (J69.-)

More specific codes under J18

Where this code sits

Chapter: 10. Diseases of the respiratory system (J00-J99)
Block: Influenza and pneumonia (J09-J18)

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Source

ICD-10-CM FY2026. Centers for Medicare & Medicaid Services (CMS) / National Center for Health Statistics (NCHS), “2026 ICD-10-CM Code Descriptions in Tabular Order” (icd10cm_order_2026.txt). Download the original file from cms.gov. Public domain (US Government work). Descriptors, billable flags and instructional notes on this page are reproduced from that file without modification. Krasyn adds no clinical guidance.