Excludes1 pair
J16- vs J18.9
J16 and J18.9 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
The official note, declared on J16
pneumonia NOS (J18.9)
J16
Pneumonia due to other infectious organisms, not elsewhere classified
Not billable
- Chapter 10
- Diseases of the respiratory system
- Section
- J09-J18
J18.9
Pneumonia, unspecified organism
BillableUnspecified
- Chapter 10
- Diseases of the respiratory system
- Section
- J09-J18
Indexed under
- Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved)
- Infection, infected, infective › lung
- Pneumonia › atypical NEC
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