ICD-10 · PDGM grouping
C79 Secondary malignant neoplasm of other and unspecified sites
All 25 codes in the C79 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
25
Can lead a claim
19
Cannot lead a claim
6
What CMS assigns to C79
19 of the 25 codes group to MMTA - Infectious Disease, Neoplasms, and Blood-Forming Diseases (17) and Neuro Rehabilitation (2); 6 are assigned no clinical group. Comorbidity subgroups: 18 toward Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone; 1 toward Secondary Neoplasm of Respiratory and GI Systems; 6 are assigned none. 19 of the 25 can lead a claim.
- Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone: can award the low comorbidity tier as a secondary diagnosis.
- Secondary Neoplasm of Respiratory and GI Systems: can award the low comorbidity tier as a secondary diagnosis.
Every code in C79
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 |
|---|---|---|---|---|
| C79.0 Secondary malignant neoplasm of kidney and renal pelvis | ||||
| C79.00 | Secondary malignant neoplasm of unspecified kidney and renal pelvisCMS: Secondary malignant neoplasm of unsp kidney and renal pelvis | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| C79.01 | Secondary malignant neoplasm of right kidney and renal pelvisCMS: Secondary malignant neoplasm of r kidney and renal pelvis | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.02 | Secondary malignant neoplasm of left kidney and renal pelvis | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.1 Secondary malignant neoplasm of bladder and other and unspecified urinary organs | ||||
| C79.10 | Secondary malignant neoplasm of unspecified urinary organs | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| C79.11 | Secondary malignant neoplasm of bladder | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.19 | Secondary malignant neoplasm of other urinary organs | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.2 | Secondary malignant neoplasm of skin | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.3 Secondary malignant neoplasm of brain and cerebral meninges | ||||
| C79.31 | Secondary malignant neoplasm of brain | Can lead a claim | B | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.32 | Secondary malignant neoplasm of cerebral meninges | Can lead a claim | B | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.4 Secondary malignant neoplasm of other and unspecified parts of nervous system | ||||
| C79.40 | Secondary malignant neoplasm of unspecified part of nervous systemCMS: Secondary malignant neoplasm of unsp part of nervous system | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| C79.49 | Secondary malignant neoplasm of other parts of nervous systemCMS: Secondary malignant neoplasm of oth parts of nervous system | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.5 Secondary malignant neoplasm of bone and bone marrow | ||||
| C79.51 | Secondary malignant neoplasm of bone | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.52 | Secondary malignant neoplasm of bone marrow | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.6 Secondary malignant neoplasm of ovary | ||||
| C79.60 | Secondary malignant neoplasm of unspecified ovary | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| C79.61 | Secondary malignant neoplasm of right ovary | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.62 | Secondary malignant neoplasm of left ovary | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.63 | Secondary malignant neoplasm of bilateral ovaries | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.7 Secondary malignant neoplasm of adrenal gland | ||||
| C79.70 | Secondary malignant neoplasm of unspecified adrenal gland | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| C79.71 | Secondary malignant neoplasm of right adrenal gland | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.72 | Secondary malignant neoplasm of left adrenal gland | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.8 Secondary malignant neoplasm of other specified sites | ||||
| C79.81 | Secondary malignant neoplasm of breast | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.82 | Secondary malignant neoplasm of genital organs | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.83 | Secondary malignant neoplasm of oral cavity | Can lead a claim | K | Secondary Neoplasm of Respiratory and GI Systems |
| C79.89 | Secondary malignant neoplasm of other specified sites | Can lead a claim | K | Secondary neoplasm of urinary and reproductive systems, skin, brain, and bone |
| C79.9 | Secondary malignant neoplasm of unspecified site | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
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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