B58.3 vs J17
B58.3 and J17 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 J17
pneumonia in toxoplasmosis (B58.3)
B58.3
Pulmonary toxoplasmosis
Billable
- Chapter 1
- Certain infectious and parasitic diseases
- Section
- B50-B64
Indexed under
- Pneumonia › in › toxoplasmosis (acute) (double) (migratory) (purulent) (septic) (unresolved)
- Pneumonitis › due to › toxoplasmosis (acute) (primary)
- Toxoplasma, toxoplasmosis › with › pneumonia, pneumonitis (acquired)
J17
Pneumonia in diseases classified elsewhere
Billable
- Chapter 10
- Diseases of the respiratory system
- Section
- J09-J18
Indexed under
- Pneumonia › postinfectional NEC (acute) (double) (migratory) (purulent) (septic) (unresolved)
- Pneumonia › rheumatic (acute) (double) (migratory) (purulent) (septic) (unresolved)
- Rheumatic › pneumonia (acute) (subacute)
- Bilharziasis › pulmonary NOS › pneumonia
- Pneumonia › in › rheumatic fever (acute) (double) (migratory) (purulent) (septic) (unresolved)
These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.
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