C63.00
BillableMalignant neoplasm of unspecified epididymis
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C63.00 an HCC code?
Yes. C63.00 maps to Prostate, Breast, and Other Cancers and Tumors under the CMS-HCC V28 risk adjustment model (and Breast, Prostate, and Other Cancers and Tumors under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for C63.00
For C63.00to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed C63.00 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C63.00 is the ICD-10-CM diagnosis code for malignant neoplasm of unspecified epididymis. Cancer of the epididymis (a tube that stores and carries sperm) when the specific side cannot be determined. C63.00 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of male genital organs (c60-c63).
Under the CMS-HCC V28 risk adjustment model, C63.00 maps to Prostate, Breast, and Other Cancers and Tumors (HCC 23) with a community, non-dual, aged base RAF weight of 0.186. Under the older CMS-HCC V24 model, C63.00 maps to Breast, Prostate, and Other Cancers and Tumors (HCC 12) with a community, non-dual, aged base RAF weight of 0.150. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
This is an unspecified laterality code; use only when the side is truly unknown or not documented. Because C63.00 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for C63.00 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is an unspecified laterality code; use only when the side is truly unknown or not documented
- •Query the provider for clarification on which epididymis is affected to assign a more specific code
Clinical Significance
Epididymal cancer is an extremely rare malignancy of the tubular structure that stores and transports sperm. Most epididymal masses are benign (adenomatoid tumors, spermatoceles), making histologic confirmation essential before assigning a malignant code. The unspecified laterality should be queried since epididymectomy is a lateralized procedure.
Documentation Requirements
- ✓Pathologic confirmation of malignancy in the epididymis (not just a mass)
- ✓Laterality — query provider
- ✓Histologic type (most common malignant types are sarcoma, mesothelioma, or metastatic carcinoma)
- ✓Whether primary or metastatic (particularly from prostate, kidney, or stomach)
- ✓Staging and treatment plan
Commonly Confused Codes
- •C63.01/C63.02 — Laterality-specific epididymis cancer; always preferred
- •D29.30 — Benign neoplasm of unspecified epididymis; most epididymal tumors are benign
- •C62.10-C62.12 — Testicular cancer; the epididymis is adjacent but anatomically distinct
- •N45.1-N45.4 — Orchitis/epididymitis; inflammatory conditions are not neoplastic