2027 ICD-10-CM Diagnosis Code J18Pneumonia, unspecified organism

ICD-10-CM Codes›J00–J99›J09-J18›J18

ICD-10-CM J18
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

J18 is a non-billable ICD-10-CM category code for pneumonia, unspecified organism, so it cannot be submitted on claims. Use a more specific code from this category instead, such as J18.0, J18.1, J18.2, and J18.8.

Code Identity

ICD-10-CM Code
J18
Billable Status
No — Non-Billable Category
Code Describes
Pneumonia, unspecified organism
Short Description
Pneumonia, unspecified organism
Same as the full description in the CMS dataset.
Chapter
J09-J18
Influenza and pneumonia

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ09-J18Influenza and pneumonia
CategoryJ18Pneumonia, unspecified organism
This CodeJ18Pneumonia, unspecified organism

Specific Coding for Pneumonia, unspecified organismOverview

Non-specific codes like J18 require more characters. Use one of these billable codes instead:

  • Use J18.0 for Bronchopneumonia, unspecified organism

  • Use J18.1 for Lobar pneumonia, unspecified organism

  • Use J18.2 for Hypostatic pneumonia, unspecified organism

  • Use J18.8 for Other pneumonia, unspecified organism

  • Use J18.9 for Pneumonia, unspecified organism

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to J18: its own notes plus those printed at block J09-J18 and Chapter 10. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

  • 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 excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

On J18 itself
  • 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)
From Block J09-J18 Influenza and pneumonia applies to 53 codes
  • allergic or eosinophilic pneumonia (J82)
  • aspiration pneumonia NOS (J69.0)
  • meconium pneumonia (P24.01)
  • neonatal aspiration pneumonia (P24.-)
  • pneumonia due to solids and liquids (J69.-)
  • congenital pneumonia (P23.9)
  • lipid pneumonia (J69.1)
  • rheumatic pneumonia (I00)
  • ventilator associated pneumonia (J95.851)
From Chapter 10 (J00-J99) Diseases of the respiratory system applies to 366 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • smoke inhalation (T59.81-)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Code First

The underlying condition named in the note is sequenced before this code.

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Block J09-J18 Influenza and pneumonia applies to 53 codes
  • code, if applicable, to identify resistance to antimicrobial drugs (Z16.-)
From Chapter 10 (J00-J99) Diseases of the respiratory system applies to 366 codes
  • code, where applicable, to identify:
  • exposure to environmental tobacco smoke (Z77.22)
  • exposure to tobacco smoke in the perinatal period (P96.81)
  • history of tobacco dependence (Z87.891)
  • occupational exposure to environmental tobacco smoke (Z57.31)
  • tobacco dependence (F17.-)
  • tobacco use (Z72.0)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

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

Notes

General instructions on how these codes are used.

From Chapter 10 (J00-J99) Diseases of the respiratory system applies to 366 codes
  • When a respiratory condition is described as occurring in more than one site and is not specifically indexed, it should be classified to the lower anatomic site (e.g. tracheobronchitis to bronchitis in J40).

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name J18, its category, or a range that includes it.

Use Additional Code 1

These codes say to use an additional code from the note, and J18 is one of the codes named.

  • J95.89 Other postprocedural complications and disorders of respiratory system, not elsewhere classified
    bacterial or viral pneumonia (J12-J18) names J12-J18, which includes this code

Code Also 1

These codes say J18 may also be needed to fully describe the condition. The note gives no sequencing direction.

  • D81.82 Activated Phosphoinositide 3-kinase Delta Syndrome [APDS]
    pneumonia (J12-J18) names J12-J18, which includes this code

Clinical InformationClinical

  • Pneumonia

    infection of the lung often accompanied by inflammation.

Patient EducationClinical

Pneumonia

Pneumonia is an infection in one or both of your lungs. It causes the air sacs of your lungs to fill up with fluid or pus. Pneumonia can range from mild to severe, depending on what caused it, your age, and your overall health.

The full article covers:

  • What is pneumonia?
  • What causes pneumonia?
  • Who is more likely to develop pneumonia?
  • What are the symptoms of pneumonia?
  • What other problems can pneumonia cause?
  • How is pneumonia diagnosed?
  • What are the treatments for pneumonia?
  • Can pneumonia be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About J18Overview

What is the ICD-10 code for pneumonia, unspecified organism?

J18 is the ICD-10-CM category for pneumonia, unspecified organism, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is J18 (Pneumonia, unspecified organism) a billable code?

No. This is a category header that groups the codes for pneumonia, unspecified organism, and headers cannot be submitted on claims. Claims for pneumonia, unspecified organism need a more specific code from this category, such as J18.0, J18.1, and J18.2.

Can J18 be reported with P23.0?

Not as a rule. The Excludes1 note on J18 lists "congenital pneumonia (P23.0)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What is coded first with J18?

The Code First note reads: if applicable, associated influenza (J09.X1, J10.0-, J11.0-). When one of these applies, it is sequenced before J18.