D03.4
BillableMelanoma in situ of scalp and neck
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D03.4 an HCC code?
Yes. D03.4 maps to Melanoma and Other Skin Cancers 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 D03.4
For D03.4 to 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 D03.4 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D03.4 is the ICD-10-CM diagnosis code for melanoma in situ of scalp and neck. Early-stage melanoma confined to the skin surface on the scalp or neck area, before spreading to deeper tissue layers. D03.4 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering in situ neoplasms (d00-d09).
Under the CMS-HCC V28 risk adjustment model, D03.4 maps to Melanoma and Other Skin Cancers (HCC 23) with a community, non-dual, aged base RAF weight of 0.251. Under the older CMS-HCC V24 model, D03.4 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 code covers both scalp and neck locations; document which specific area (scalp vs. neck) in the medical record for clinical clarity. Because D03.4 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 D03.4 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code covers both scalp and neck locations; document which specific area (scalp vs. neck) in the medical record for clinical clarity
- •Scalp melanomas may have different prognosis considerations compared to other body sites
Clinical Significance
Melanoma in situ of the scalp and neck represents early-stage melanocytic malignancy confined to the epidermis of these sun-exposed areas. Scalp melanomas are associated with poorer outcomes when they progress to invasive disease compared to other body sites, making early detection at the in situ stage particularly valuable. The scalp is often a hidden site where melanoma may go undetected due to hair coverage.
Documentation Requirements
- ✓Biopsy-confirmed melanoma in situ with documentation of the specific location (scalp vs.
- ✓posterior neck vs.
- ✓lateral neck).
- ✓Margin status after excision is critical, particularly on the scalp where subclinical extension is common.
- ✓Document any challenges related to hair-bearing skin and the chosen excision technique.