Reserved for future guideline expansion
K65.9
BookmarkPeritonitis, unspecified
Filed alongside this entry 2
under Hemoperitoneum
Index entries, exactly as the book files them. This says they are listed together — not that any of them is documented in your chart.
Billable FY2027 2026-10-01 → 2027-09-30
This is the unspecified option. 6 more
specific codes sit alongside it. Worth
checking whether the documentation supports one of them.
How to use this page
Everything the published sources say about one code, on one page.
- Read the Excludes1 block first — it is the one that stops you coding this at all alongside another code.
- Excludes2, Code first, Use additional and Includes follow. A note inherited from a parent category is labelled with the category it came from, so you can see why it applies.
- Official Guidelines sit below. "Guidelines naming this code" cite the code or a range containing it; "Chapter guidance" is the general guidance for its chapter and is the weaker signal.
- Guideline text is quoted verbatim with its section number and page, so you can check it against the published document.
- Risk-model chips show which published CMS models map this code.
What this page does not do
- Guidance is quoted, never paraphrased — a paraphrase of a coding rule is a different rule.
- Medication candidates, where shown, are matched by condition *name* and are offered as candidates for you to judge. They are not "the drugs for this code".
Exclusions25never code together
K65code
Excludes1
- acute appendicitis with generalized peritonitis (K35.2-)K35.2-
- aseptic peritonitis (T81.6)T81.6
- benign paroxysmal peritonitis (E85.0)E85.0
- chemical peritonitis (T81.6)T81.6
- gonococcal peritonitis (A54.85)A54.85
- neonatal peritonitis (P78.0-P78.1)P78.0-P78.1
- pelvic peritonitis, female (N73.3-N73.5)N73.3-N73.5
- periodic familial peritonitis (E85.0)E85.0
- peritonitis due to talc or other foreign substance (T81.6)T81.6
- peritonitis in chlamydia (A74.81)A74.81
- peritonitis in diphtheria (A36.89)A36.89
- peritonitis in syphilis (late) (A52.74)A52.74
- peritonitis in tuberculosis (A18.31)A18.31
- peritonitis with or following abortion or ectopic or molar pregnancy (O00-O07, O08.0)O00-O07O08.0
- peritonitis with or following appendicitis (K35.-)K35.-
- puerperal peritonitis (O85)O85
- retroperitoneal infections (K68.-)K68.-
K00-K95chapter
Excludes2
- certain conditions originating in the perinatal period (P04-P96)P04-P96
- certain infectious and parasitic diseases (A00-B99)A00-B99
- complications of pregnancy, childbirth and the puerperium (O00-O9A)O00-O9A
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)Q00-Q99
- endocrine, nutritional and metabolic diseases (E00-E88)E00-E88
- injury, poisoning and certain other consequences of external causes (S00-T88)S00-T88
- neoplasms (C00-D49)C00-D49
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)R00-R94
Excludes1 — never code together. The excluded condition and this one are mutually exclusive.
Excludes2 — not included here, but the patient may have both. Code both when documented.
Instructional notes3
Official Guidelines1names this code
ICD-10-CM Official Guidelines for Coding and Reporting, quoted in full. Published by CMS and NCHS; in the public domain.
Index entries leading here3
Alongside this code6same parent — K65
Medications1
MED-RT files conditions by MeSH, which carves the world differently from ICD-10. These are name matches on this code's description, offered as candidates — not as an assertion that they are this code.
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.