ICDcodes.org
FY2027

J16.0 vs J17

J16.0 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
chlamydial pneumonia (J16.0)
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)
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)

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