C43.4 ICD-10-CM Code: Malignant melanoma of scalp and neck
C43.4 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 · HCC coding software
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Neoplasms (C00-D49) / Melanoma and other malignant neoplasms of skin (C43-C44)
C43.4
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceMalignant melanoma of scalp and neck
A type of skin cancer (melanoma) that starts on the scalp (top of the head) or neck.
Buddy Insight
Malignant melanoma of the scalp and neck.
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 C43.4. Check the code and parent instructions in the Code Book.
Excludes 2
Official- malignant melanoma of skin of genital organs (C51-C52, C60.-, C63.-)Inherited from C43
- Merkel cell carcinoma (C4A.-)Inherited from C43
- sites other than skin-code to malignant neoplasm of the siteInherited from C43
Related Codes
Includes
OfficialNo Includes notes are included in this display for C43.4. Check the code and parent instructions in the Code Book.
Excludes 1
Official- melanoma in situ (D03.-)Inherited from C43
Code First
OfficialNo Code First sequencing instructions are included in this display for C43.4. Check the code and parent instructions in the Code Book.
Use Additional
OfficialNo Use Additional Code instructions are included in this display for C43.4. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for C43.4. 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 C43.4 an HCC code?
Yes. C43.4 (Malignant melanoma of scalp and neck) 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: C43.4 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
- C43.4
- Description
- Malignant melanoma of scalp and neck
- 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 C43.4 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for C43.4
For C43.4, 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
Get the V28 mapping + MEAT cheat sheet
One printable reference: check representative V28 mappings and the documentation reminders your note needs. Free, no card.
Free PDF. No card. Unsubscribe anytime.
What This Code Means
C43.4 is the ICD-10-CM diagnosis code for malignant melanoma of scalp and neck. A type of skin cancer (melanoma) that starts on the scalp (top of the head) or neck. C43.4 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering melanoma and other malignant neoplasms of skin (c43-c44).
Under the CMS-HCC V28 risk adjustment model, C43.4 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 code combines both scalp and neck locations; documentation should clarify which area is affected. For C43.4, 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 C43.4 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code combines both scalp and neck locations; documentation should clarify which area is affected
- •Ensure the melanoma is not on the face or ears, which have separate codes
Clinical Significance
Malignant melanoma of the scalp and neck. The scalp is one of the most dangerous sites for melanoma, with scalp melanomas carrying significantly worse prognosis than melanomas at most other body sites — studies show up to twice the mortality rate. This is attributed to the rich vascular supply of the scalp and delayed detection under hair-covered skin.
Documentation Requirements
- ✓Specific location (scalp vertex, temporal scalp, occipital scalp, anterior neck, posterior neck, lateral neck)
- ✓Breslow depth — particularly critical given the aggressive behavior of scalp melanoma
- ✓Ulceration status and mitotic rate
- ✓Sentinel lymph node biopsy results (multiple drainage basins possible for scalp)
- ✓AJCC staging
- ✓Hair-bearing vs. non-hair-bearing scalp
Commonly Confused Codes
- •C43.39: Melanoma of other parts of face; the junction between face and scalp (forehead/hairline) can be ambiguous
- •C43.21/C43.22: Melanoma of ear; postauricular melanoma may be classified as scalp/neck or ear
- •C43.30: Melanoma of unspecified face; face vs. scalp distinction at the hairline
- •D03.4: Melanoma in situ of scalp and neck; non-invasive, no HCC mapping