Condition guide
Breast Cancer HCC Coding Guide
Breast Cancer (e.g. C50.011) maps to HCC 23 (Prostate, Breast, and Other Cancers and Tumors) under CMS-HCC V28. Its source-labeled community non-dual aged reference coefficient is 0.186. This is not a member total; full contribution depends on hierarchy, cleanup, interactions, member context, and model year. Z85.3, personal history of malignant neoplasm of breast, is non-HCC under V28. It can also map to HCC 18 (Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid) when the documentation supports those manifestations.
Quick Facts
HCC Categories
HCC 18, Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid
HCC 23, Prostate, Breast, and Other Cancers and Tumors
RAF Weight Range
0.186 to 2.341
Community, non-dual, aged (V28)
Model
CMS-HCC V28 (PY2026, 100% phase-in)
9 ICD-10 codes map to payment HCCs
What HCC category does Breast Cancer map to under V28?
Breast cancer is the most commonly diagnosed cancer in women in the United States. Under CMS-HCC V28, an active primary breast malignancy (C50.x) maps to HCC 23, "Prostate, Breast, and Other Cancers and Tumors," which carries a community non-dual aged RAF of 0.186. The picture changes when distant spread is documented. A secondary (metastatic) neoplasm code such as C79.81 maps to HCC 18, "Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer," at a much higher RAF of 2.341. So a single patient's codes can land in two HCCs. Coders must verify disease status at every encounter, because personal history of breast cancer (Z85.3) carries no HCC once disease is no longer active.
ICD-10 to HCC Mapping
| ICD-10 Code | Description | Billable | HCC Mapping |
|---|---|---|---|
| C50.011 | Malignant neoplasm of nipple and areola, right female breast | Yes | HCC 23 |
| C50.012 | Malignant neoplasm of nipple and areola, left female breast | Yes | HCC 23 |
| C50.411 | Malignant neoplasm of upper-outer quadrant of right female breast | Yes | HCC 23 |
| C50.412 | Malignant neoplasm of upper-outer quadrant of left female breast | Yes | HCC 23 |
| C50.911 | Malignant neoplasm of unspecified site of right female breast | Yes | HCC 23 |
| C50.912 | Malignant neoplasm of unspecified site of left female breast | Yes | HCC 23 |
| C50.919 | Malignant neoplasm of unspecified site of unspecified female breast | Yes | HCC 23 |
| C50.419 | Malignant neoplasm of upper-outer quadrant of unspecified female breast | Yes | HCC 23 |
| C79.81 | Secondary malignant neoplasm of breast | Yes | HCC 18 |
| Z85.3 | Personal history of malignant neoplasm of breast | Yes | No HCC (not risk-adjusting under V28) |
Displayed numbers are source-labeled community non-dual aged reference coefficients from CMS-HCC V28, not member totals.
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Coder workflow notes
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Documentation Tips
Document the specific quadrant or site within the breast: upper-outer, upper-inner, lower-outer, lower-inner, central, or axillary tail.
Always specify laterality: right, left, or bilateral, unspecified laterality results in less specific codes.
Clearly document whether the breast cancer is currently active (under treatment or surveillance) or represents personal history.
Record the receptor status (ER, PR, HER2) when available, as it supports the specificity of documentation.
Document current treatment modality: surgery, chemotherapy, radiation, hormonal therapy, or immunotherapy.
Code metastatic sites (C77-C79) separately when distant metastases are documented.
Common Coding Mistakes
Coding active breast cancer (C50.x) for a patient who completed treatment and is in remission, use personal history Z85.3 when cancer is no longer active.
Failing to specify laterality, resulting in unspecified-side codes that reduce clinical specificity.
Not coding the quadrant when it is documented in surgical pathology or imaging reports.
Missing metastatic site codes when the patient has documented distant disease (bone, liver, brain, lung metastases).
V24 to V28 Changes
Under CMS-HCC V28, active primary breast cancer (C50.x) maps to HCC 23, "Prostate, Breast, and Other Cancers and Tumors." A supported secondary neoplasm code such as C79.81 maps to HCC 18. Capture the active primary and documented distant spread, then apply the complete diagnosis set, hierarchy, cleanup, interactions, and member-segment coefficient table. Do not infer an additive RAF total from the two codes alone.
Related Conditions
Related references
Sources
Displayed numbers are source-labeled community non-dual aged reference coefficients from CMS-HCC V28, not member totals.
Verified current to CMS-HCC V28, payment year 2026 — last reviewed September 5, 2026.
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