C63.00 ICD-10-CM Code: Malignant neoplasm of unspecified epididymis
C63.00 maps to CMS-HCC V28 23. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · free HCC coding tools
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FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of male genital organs (C60-C63)
C63.00
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceMalignant neoplasm of unspecified epididymis
Cancer of the epididymis (a tube that stores and carries sperm) when the specific side cannot be determined.
Buddy Insight
Epididymal cancer is an extremely rare malignancy of the tubular structure that stores and transports sperm.
CMS-HCC V28
MappedHCC 23
Coefficient HCC 23: 0.186 (Community Non-Dual Aged (CNA))
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
MappedHCC 013
Code-level coefficient reference
ESRD/PACE
MappedHCC 12
Code-level coefficient reference
RXHCC
MappedHCC 22
Code-level coefficient reference
Code Book Path
Inclusion Terms
OfficialNo inclusion terms are included in this display for C63.00. Check the code and parent instructions in the Code Book.
Excludes 2
OfficialNo Excludes 2 notes are included in this display for C63.00. Check the code and parent instructions in the Code Book.
Related Codes
Includes
Official- malignant neoplasm of skin of male genital organsInherited from C60-C63
Excludes 1
OfficialNo Excludes 1 notes are included in this display for C63.00. Check the code and parent instructions in the Code Book.
Code First
OfficialNo Code First sequencing instructions are included in this display for C63.00. Check the code and parent instructions in the Code Book.
Use Additional
OfficialNo Use Additional Code instructions are included in this display for C63.00. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for C63.00. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is C63.00 an HCC code?
Yes. C63.00 (Malignant neoplasm of unspecified epididymis) maps to HCC 23, Prostate, Breast, and Other Cancers and Tumors under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.186. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.
Coder answer: C63.00 is billable and maps to V28 HCC 23, Prostate, Breast, and Other Cancers and Tumors. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.
- Code
- C63.00
- Description
- Malignant neoplasm of unspecified epididymis
- HCC (V28)
- HCC 23 — Prostate, Breast, and Other Cancers and Tumors
- RAF reference coefficient
- 0.186
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.
Work C63.00 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for C63.00
For C63.00, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.
- 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
Coder workflow notes
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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 source-labeled community, non-dual, aged reference coefficient of 0.186. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.
This is an unspecified laterality code; use only when the side is truly unknown or not documented. For C63.00, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. 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, source-labeled coefficient references, 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