ICD-10 · PDGM grouping
C18 Malignant neoplasm of colon
All 10 codes in the C18 family, with the PDGM clinical group, comorbidity subgroup and primary-position rule CMS assigns, read from the CMS grouper crosswalk v07.2.26 and the CDC FY2027 code file.
Codes in family
10
Can lead a claim
10
Cannot lead a claim
0
What CMS assigns to C18
All 10 codes group to MMTA - Infectious Disease, Neoplasms, and Blood-Forming Diseases. All 10 count toward the Malignant neoplasm of Digestive Organs, includes Gastrointestinal Cancers comorbidity subgroup. Every code can lead a claim.
- Malignant neoplasm of Digestive Organs, includes Gastrointestinal Cancers: can award the low comorbidity tier as a secondary diagnosis.
Every code in C18
Descriptions are CDC’s FY2027 wording; where CMS’s grouper abbreviates one, its form is shown beneath.
| Code | Description | Primary position | Clinical group | Comorbidity subgroup |
|---|---|---|---|---|
| C18.0 | Malignant neoplasm of cecum | Can lead a claim | K | Malignant neoplasm of Digestive Organs, includes Gastrointestinal Cancers |
| C18.1 | Malignant neoplasm of appendix | Can lead a claim | K | Malignant neoplasm of Digestive Organs, includes Gastrointestinal Cancers |
| C18.2 | Malignant neoplasm of ascending colon | Can lead a claim | K | Malignant neoplasm of Digestive Organs, includes Gastrointestinal Cancers |
| C18.3 | Malignant neoplasm of hepatic flexure | Can lead a claim | K | Malignant neoplasm of Digestive Organs, includes Gastrointestinal Cancers |
| C18.4 | Malignant neoplasm of transverse colon | Can lead a claim | K | Malignant neoplasm of Digestive Organs, includes Gastrointestinal Cancers |
| C18.5 | Malignant neoplasm of splenic flexure | Can lead a claim | K | Malignant neoplasm of Digestive Organs, includes Gastrointestinal Cancers |
| C18.6 | Malignant neoplasm of descending colon | Can lead a claim | K | Malignant neoplasm of Digestive Organs, includes Gastrointestinal Cancers |
| C18.7 | Malignant neoplasm of sigmoid colon | Can lead a claim | K | Malignant neoplasm of Digestive Organs, includes Gastrointestinal Cancers |
| C18.8 | Malignant neoplasm of overlapping sites of colon | Can lead a claim | K | Malignant neoplasm of Digestive Organs, includes Gastrointestinal Cancers |
| C18.9 | Malignant neoplasm of colon, unspecified | Can lead a claim | K | Malignant neoplasm of Digestive Organs, includes Gastrointestinal Cancers |
Sources: CMS HH PPS Grouper Software v07.2.26, effective 2026-10-01, for the clinical group, comorbidity subgroup, code-first conventions and primary-position flags; CDC NCHS ICD-10-CM FY2027 code descriptions for the family title and code wording. 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.
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