ICD-10-CM 2027
ICD-10 code for Lobar pneumonia
From the official ICD-10-CM alphabetic index entry “Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved) › lobar (disseminated) (double) (interstitial)”. Page updated September 29, 2026.
About coding Lobar pneumonia
The ICD-10-CM code for Lobar pneumonia is J18.1 (Lobar pneumonia, unspecified organism). The official index lists 13 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on J18.1.
Within J18, choose J18.1 (Lobar pneumonia, unspecified organism) only when documentation doesn't support a more specific option: Bronchopneumonia, unspecified organism (J18.0), Hypostatic pneumonia, unspecified organism (J18.2), other pneumonia, unspecified organism (J18.8) and pneumonia, unspecified organism (J18.9).
Code first: , if applicable, associated influenza (J09.X1, J10.0-, J11.0-).
As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.
More specific Lobar pneumonia codes (official index)
- bacterial J15.9 — Unspecified bacterial pneumonia
- specified NEC J15.8 — Pneumonia due to other specified bacteria
- chronic
- Escherichia coli (E. coli) J15.5 — Pneumonia due to Escherichia coli
- Friedländer's bacillus J15.0 — Pneumonia due to Klebsiella pneumoniae
- Hemophilus influenzae J14 — Pneumonia due to Hemophilus influenzae
- hypostatic J18.2 — Hypostatic pneumonia, unspecified organism
- Klebsiella (pneumoniae) J15.0 — Pneumonia due to Klebsiella pneumoniae
- pneumococcal J13 — Pneumonia due to Streptococcus pneumoniae
- Proteus J15.69 — Pneumonia due to other Gram-negative bacteria
- Pseudomonas J15.1 — Pneumonia due to Pseudomonas
- specified organism NEC J16.8 — Pneumonia due to other specified infectious organisms
- staphylococcal
- streptococcal NEC J15.4 — Pneumonia due to other streptococci
- Streptococcus pneumoniae J13 — Pneumonia due to Streptococcus pneumoniae
- viral, virus
Common questions about Lobar pneumonia ICD-10 codes
What is the ICD-10 code for Lobar pneumonia?
- J18.1 — Lobar pneumonia, unspecified organism. More specific codes apply when the documentation supports them: J15.9, J15.8, J15.5, J15.0 and others below.
What is the ICD-10 code for bacterial lobar pneumonia?
- J15.9 — Unspecified bacterial pneumonia.
What is the ICD-10 code for escherichia coli lobar pneumonia?
- J15.5 — Pneumonia due to Escherichia coli.
What is the ICD-10 code for friedländer's bacillus lobar pneumonia?
- J15.0 — Pneumonia due to Klebsiella pneumoniae.
What is the ICD-10 code for hemophilus influenzae lobar pneumonia?
- J14 — Pneumonia due to Hemophilus influenzae.
What is the ICD-10 code for hypostatic lobar pneumonia?
- J18.2 — Hypostatic pneumonia, unspecified organism.
What is the ICD-10 code for klebsiella lobar pneumonia?
- J15.0 — Pneumonia due to Klebsiella pneumoniae.
Is J18.1 billable?
- Yes. J18.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can J18.1 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict J18.1 as a principal diagnosis.
Is J18.1 a CC or MCC?
- J18.1 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.