C43.0 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 Buddy coding tools

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupC43.0

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Neoplasms (C00-D49) / Melanoma and other malignant neoplasms of skin (C43-C44)

C43.0

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Malignant melanoma of lip

A malignant (cancerous) tumor of the skin on the lip that arises from melanocytes, the cells that produce skin pigment. This is a serious form of skin cancer that requires prompt treatment.

Buddy Insight

Malignant melanoma of the lip is an uncommon site for melanoma but carries significant clinical importance due to its visibility and potential for metastasis.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 23

Prostate, Breast, and Other C...

Coefficient HCC 23: 0.186 (Community Non-Dual Aged (CNA))

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 013

HHS-HCC 013 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 12

Breast/Prostate/and Other Can...

Code-level coefficient reference

RXHCC

Mapped

HCC 22

Prostate, Breast, Bladder, an...

Code-level coefficient reference

Code Book Path

Official

C43Malignant melanoma of skin C43.0Malignant melanoma of lip

Inclusion Terms

Official

No inclusion terms are included in this display for C43.0. 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

Official

C43.1Malignant melanoma of eyelid, including canthus C43.2Malignant melanoma of ear and external auricular canal C43.3Malignant melanoma of other and unspecified parts of face C43.4Malignant melanoma of scalp and neck C43.5Malignant melanoma of trunk

Includes

Official

No Includes notes are included in this display for C43.0. Check the code and parent instructions in the Code Book.

Excludes 1

Official

malignant neoplasm of vermilion border of lip (C00.0-C00.2)
melanoma in situ (D03.-)Inherited from C43

Code First

Official

No Code First sequencing instructions are included in this display for C43.0. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for C43.0. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for C43.0. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Specific location on the lip (upper vs. lower lip, vermilion border, mucosal vs. cutaneous surface)

Breslow depth (thickness in millimeters) — the most important prognostic factor

Clark level of invasion

Ulceration status (present or absent)

MEAT Support

HCC Buddy guidance

Specific location on the lip (upper vs. lower lip, vermilion border, mucosal vs. cutaneous surface)

Breslow depth (thickness in millimeters) — the most important prognostic factor

Clark level of invasion

Ulceration status (present or absent)

Audit Caution

HCC Buddy guidance

Confusing melanoma (C43.0) with non-melanoma skin cancer of the lip (C00.x) — histology is the differentiator

Coding melanoma in situ as invasive melanoma — in situ uses D03.0 and does NOT map to an HCC

Failing to distinguish lip melanoma from mucosal melanoma of the oral cavity (C03-C06)

Not confirming melanoma histology by pathology — clinical appearance alone is insufficient

Common Mistakes

HCC Buddy guidance

C00.x — Malignant neoplasm of lip (non-melanoma skin cancer or squamous cell carcinoma of lip); different histology

C43.39 — Malignant melanoma of other parts of face; for melanoma of adjacent facial skin, not lip

D03.0 — Melanoma in situ of lip; for non-invasive melanoma confined to the epidermis

D22.0 — Melanocytic nevi of lip; benign mole vs. melanoma

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 C43.0 an HCC code?

Yes. C43.0 (Malignant melanoma of lip) 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: C43.0 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: C43.0
Description: Malignant melanoma of lip
HCC (V28): HCC 23 — Prostate, Breast, and Other Cancers and Tumors
RAF reference coefficient: 0.186
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 23, Prostate, Breast, and Other Cancers and Tumors

0.186

ESRDHCC 12, Breast/Prostate/and Other Cancers and Tumors

Not separately weighted

RxHCCHCC 22, Prostate, Breast, Bladder, and Other Cancers and Tumors

Not separately weighted

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 C43.0 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for C43.0

For C43.0, 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

C43.0 is the ICD-10-CM diagnosis code for malignant melanoma of lip. A malignant (cancerous) tumor of the skin on the lip that arises from melanocytes, the cells that produce skin pigment. This is a serious form of skin cancer that requires prompt treatment. C43.0 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, C43.0 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.

Verify the specific lip location (upper or lower) in the documentation, as this may affect staging and treatment planning. For C43.0, 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 C43.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify the specific lip location (upper or lower) in the documentation, as this may affect staging and treatment planning
•Ensure this code is not confused with other skin cancers of the lip (such as squamous cell carcinoma) by confirming the histological diagnosis of melanoma in the medical record

Clinical Significance

Malignant melanoma of the lip is an uncommon site for melanoma but carries significant clinical importance due to its visibility and potential for metastasis. Lip melanomas may arise from mucosal or cutaneous surfaces and have different prognostic implications than other skin melanomas. Early detection and wide excision with sentinel lymph node evaluation are standard of care.

Documentation Requirements

✓Specific location on the lip (upper vs. lower lip, vermilion border, mucosal vs. cutaneous surface)
✓Breslow depth (thickness in millimeters) — the most important prognostic factor
✓Clark level of invasion
✓Ulceration status (present or absent)
✓Mitotic rate
✓Sentinel lymph node biopsy results if performed
✓AJCC staging (TNM)

Excludes 1, Do NOT code together

malignant neoplasm of vermilion border of lip (C00.0-C00.2)

Commonly Confused Codes

•C00.x: Malignant neoplasm of lip (non-melanoma skin cancer or squamous cell carcinoma of lip); different histology
•C43.39: Malignant melanoma of other parts of face; for melanoma of adjacent facial skin, not lip
•D03.0: Melanoma in situ of lip; for non-invasive melanoma confined to the epidermis
•D22.0: Melanocytic nevi of lip; benign mole vs. melanoma