J15 vs J16.0
J15 and J16.0 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on J15
chlamydial pneumonia (J16.0)
J15
Bacterial pneumonia, not elsewhere classified
Not billable
- Chapter 10
- Diseases of the respiratory system
- Section
- J09-J18
Use when the record says
- bronchopneumonia due to bacteria other than S. pneumoniae and H. influenzae
J16.0
Chlamydial pneumonia
Billable
- Chapter 10
- Diseases of the respiratory system
- Section
- J09-J18
Indexed under
- Pneumonia › chlamydial (acute) (double) (migratory) (purulent) (septic) (unresolved)
- Pneumonia › in › Chlamydia (acute) (double) (migratory) (purulent) (septic) (unresolved)
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027