K65-K6A — Diseases of peritoneum and retroperitoneum
Codes in range
21
No clinical group
2
A period cannot be grouped from these.
Barred as primary
0
CMS rejects these in the primary position.
Where these codes group
19 of the 21 codes in K65-K6A group to MMTA - Gastrointestinal tract and Genitourinary system. A further 2 are assigned no clinical group at all, which means a 30-day period cannot be grouped from them.
Code families in K65-K6A
One page per three-character family: every code in it, whether it can lead a claim, its clinical group and comorbidity subgroup.
Every code in K65-K6A
Descriptions are CMS’s own, abbreviated as CMS abbreviates them.
| Code | Description | Clinical group | Primary position |
|---|---|---|---|
| K650 | Generalized (acute) peritonitis | J | Can lead a claim |
| K651 | Peritoneal abscess | J | Can lead a claim |
| K652 | Spontaneous bacterial peritonitis | J | Can lead a claim |
| K653 | Choleperitonitis | J | Can lead a claim |
| K654 | Sclerosing mesenteritis | J | Can lead a claim |
| K658 | Other peritonitis | J | Can lead a claim |
| K659 | Peritonitis, unspecified | J | Can lead a claim |
| K660 | Peritoneal adhesions (postprocedural) (postinfection) | J | Can lead a claim |
| K661 | Hemoperitoneum | J | Can lead a claim |
| K668 | Other specified disorders of peritoneum | J | Can lead a claim |
| K669 | Disorder of peritoneum, unspecified | None | Cannot lead a claim |
| K67 | Disorders of peritoneum in infectious diseases classd elswhr | None | Cannot lead a claim |
| K6811 | Postprocedural retroperitoneal abscess | J | Can lead a claim |
| K6812 | Psoas muscle abscess | J | Can lead a claim |
| K6819 | Other retroperitoneal abscess | J | Can lead a claim |
| K682 | Retroperitoneal fibrosis | J | Can lead a claim |
| K683 | Retroperitoneal hematoma | J | Can lead a claim |
| K689 | Other disorders of retroperitoneum | J | Can lead a claim |
| K6A01 | Prevesical abscess | J | Can lead a claim |
| K6A09 | Other pelvic abscess | J | Can lead a claim |
| K6A8 | Other diseases of the pelvis, not elsewhere classified | J | Can lead a claim |
Source: CMS HH PPS Grouper Software v07.2.26, effective 2026-10-01. This is the crosswalk Medicare runs a claim through. Grouping also depends on admission source, timing, the OASIS functional items and the rest of the diagnosis list.