ICD-10-CM 2027
ICD-10 code for bacillus pneumonia
From the official ICD-10-CM alphabetic index entry “Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved) › bacillus”. Page updated September 29, 2026.
About coding bacillus pneumonia
The ICD-10-CM code for bacillus pneumonia is J15.9 (Unspecified bacterial pneumonia). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on J15.9.
Within J15, choose J15.9 (Unspecified bacterial pneumonia) only when documentation doesn't support a more specific option: pneumonia due to Klebsiella pneumoniae (J15.0), pneumonia due to Pseudomonas (J15.1), pneumonia due to staphylococcus (J15.2), pneumonia due to streptococcus, group B (J15.3), pneumonia due to other streptococci (J15.4), pneumonia due to Escherichia coli (J15.5), pneumonia due to other Gram-negative bacteria (J15.6), pneumonia due to Mycoplasma pneumoniae (J15.7) and 1 more.
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 bacillus pneumonia codes (official index)
- specified NEC J15.8 — Pneumonia due to other specified bacteria
Common questions about bacillus pneumonia ICD-10 codes
What is the ICD-10 code for bacillus pneumonia?
- J15.9 — Unspecified bacterial pneumonia. More specific codes apply when the documentation supports them: J15.8.
Is J15.9 billable?
- Yes. J15.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can J15.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict J15.9 as a principal diagnosis.
Is J15.9 a CC or MCC?
- J15.9 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.