Breast Cancer HCC Coding Guide
Complete HCC coding guide for Breast Cancer (C50.x) including ICD-10 to HCC mapping, V28 RAF weights, laterality documentation, and active vs. history coding.
Quick Facts
HCC Categories
HCC 23 — Breast, Prostate, Colorectal and Other Cancers and Tumors
RAF Weight Range
0.316
Community, non-dual, aged (V28)
Model
CMS-HCC V28 (PY2026 — 100% phase-in)
9 ICD-10 codes map to payment HCCs
Overview
Breast cancer is the most commonly diagnosed cancer in women, with approximately 310,000 new cases annually in the United States. Under CMS-HCC V28, breast cancer maps to HCC 22 (Lymphoma and Other Cancers) or HCC 23 (Breast, Prostate, Colorectal and Other Cancers and Tumors) depending on the model year and specific code. Accurate coding requires documenting the specific anatomical site within the breast, laterality, and whether the diagnosis represents active disease or personal history. The distinction between active malignancy (C50.x) and personal history of breast cancer (Z85.3) is critical for risk adjustment. Coders must verify the disease status at each encounter and code accordingly.
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 22 |
| Z85.3 | Personal history of malignant neoplasm of breast | Yes | No HCC |
RAF weights are community, non-dual, aged base coefficients from the CMS-HCC V28 model (PY2026). Verify against the latest CMS rate announcement for payment calculations.
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
V28 maps breast cancer to HCC 23 (Breast, Prostate, Colorectal and Other Cancers and Tumors), which represents a lower-tier cancer HCC compared to the severe cancers in HCC 21. Under V24, breast cancer mapped to HCC 12 (Breast, Prostate, and Other Cancers and Tumors). The V28 recalibration adjusted RAF weights to reflect updated cost data. The cancer hierarchy in V28 places greater emphasis on distinguishing active treatment from surveillance, and severe cancers from less resource-intensive malignancies.
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