Peritonitis, unspecified
Diseases of the Digestive System·Peritonitis·subcategory·FY 2027
Peritoneal Disorders: Your peritoneum is the tissue that lines your abdominal wall and covers most of the organs in your abdomen. A liquid, peritoneal fluid, lubricates the surface of this tissue.
Read more about peritoneal disorders on MedlinePlus · Source: MedlinePlus, National Library of Medicine
Also indexed as: Fistula, peritoneum; Hemoperitoneum, infectional; Peritonitis
Instructional notes
Includes: conditions that are coded here
- Bacterial peritonitis NOS
Also applies, from K65: Peritonitis
These notes sit on K65 and apply to every code under it, including K65.9.
Excludes1: not coded here, use a different code
- acute appendicitis with generalized peritonitis (K35.2-)
- aseptic peritonitis (T81.6)
- benign paroxysmal peritonitis (E85.0)
- chemical peritonitis (T81.6)
- gonococcal peritonitis (A54.85)
- neonatal peritonitis (P78.0-P78.1)
- pelvic peritonitis, female (N73.3-N73.5)
- periodic familial peritonitis (E85.0)
- peritonitis due to talc or other foreign substance (T81.6)
- peritonitis in chlamydia (A74.81)
- peritonitis in diphtheria (A36.89)
- peritonitis in syphilis (late) (A52.74)
- peritonitis in tuberculosis (A18.31)
- peritonitis with or following abortion or ectopic or molar pregnancy (O00-O07, O08.0)
- peritonitis with or following appendicitis (K35.-)
- puerperal peritonitis (O85)
- retroperitoneal infections (K68.-)
Code also: add a code for this too, order depends on the encounter
- if applicable diverticular disease of intestine (K57.-)
Use additional code: add a second code for this, listed after this one
- code (B95-B97), to identify infectious agent, if known
Where K65.9 sits
- K65-K6A Diseases of peritoneum, retroperitoneum and pelvis (K65-K6A)
- K65 Peritonitis
- K65.9 Peritonitis, unspecified
MS-DRGs
As the principal diagnosis, this code groups to these MS-DRGs (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.
- DRG 371 Major Gastrointestinal Disorders and Peritoneal Infections with MCC
- DRG 372 Major Gastrointestinal Disorders and Peritoneal Infections with CC
- DRG 373 Major Gastrointestinal Disorders and Peritoneal Infections without CC/MCC
- DRG 791 Prematurity with Major Problems
- DRG 793 Full Term Neonate with Major Problems
Codes whose notes mention K65.9
If you are coding one of these, its note tells you to add K65.9 too (Code Also, Use Additional Code), code it first (Code First), or not use it together (Excludes1).
- K65.2 Excludes1: bacterial peritonitis NOS (K65.9)
ICD-9-CM equivalent
Legacy crosswalk from the CMS General Equivalence Mappings (last updated 2018).
- 567.9 Unspecified peritonitis