K65.2 vs K65.9
K65.2 and K65.9 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 K65.2
bacterial peritonitis NOS (K65.9)
K65.2
Spontaneous bacterial peritonitis
Billable
- Chapter 11
- Diseases of the digestive system
- Section
- K65-K6A
Indexed under
- Peritonitis › spontaneous bacterial (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion)
K65.9
Peritonitis, unspecified
BillableUnspecified
- Chapter 11
- Diseases of the digestive system
- Section
- K65-K6A
Use when the record says
- Bacterial peritonitis NOS
Indexed under
- Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion)
- Fistula › peritoneum (cutaneous)
- Hemoperitoneum › infectional
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