What is ICD-10 code C02.3?

C02.3 is the ICD-10-CM diagnosis code for Malignant neoplasm of anterior two-thirds of tongue, part unspecified. Cancer of the front two-thirds of the tongue when the exact surface location is not specified. It belongs to the ICD-10-CM chapter for neoplasms (c00-d49). C02.3 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C02.3 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. C02.3 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. C02.3 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does C02.3 map to under V28?

C02.3 maps to CMS-HCC V28 HCC 21 (Lymphoma and Other Cancers). The category numbers, labels, and conditions come from the CMS-HCC V28 model file for payment year 2026.

2026 ICD-10-CM C02.3: Malignant neoplasm

C02.3 maps to CMS-HCC V28 21. A source-labeled RAF reference is available. Documentation must support MEAT. MEAT criteria · RAF Calculator · HCC coding software

ICD-10-CM Code View

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

Code lookupC02.3Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of lip, oral cavity and pharynx (C00-C14)

C02.3

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

Malignant neoplasm of anterior two-thirds of tongue, part unspecified

Cancer of the front two-thirds of the tongue when the exact surface location is not specified.

Buddy Insight

CMS-HCC V28

Mapped

HCC 21

Lymphoma and Other Cancers

Code-level coefficient reference

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 011

HHS-HCC 011 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 11

Colorectal/Bladder/and Other ...

Code-level coefficient reference

RXHCC

Mapped

HCC 22

Prostate, Breast, Bladder, an...

Code-level coefficient reference

Code Book Path

Official

C02Malignant neoplasm of other and unspecified parts of tongue

C02.3Malignant neoplasm of anterior two-thirds of tongue, part unspecified

Inclusion Terms

Official

Malignant neoplasm of middle third of tongue NOS
Malignant neoplasm of mobile part of tongue NOS

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for C02.3 in this effective period.

Related Child Codes

Official

C02.0Malignant neoplasm of dorsal surface of tongue

C02.1Malignant neoplasm of border of tongue

C02.2Malignant neoplasm of ventral surface of tongue

C02.4Malignant neoplasm of lingual tonsil

C02.8Malignant neoplasm of overlapping sites of tongue

Includes

Official

ICD-10-CM does not list Includes notes for C02.3 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for C02.3 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for C02.3 in this effective period.

Use Additional

Official

code to identify:
alcohol abuse and dependence (F10.-)
history of tobacco dependence (Z87.891)
tobacco dependence (F17.-)
tobacco use (Z72.0)

Code Also

Official

ICD-10-CM does not list Code Also instructions for C02.3 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Pathology confirming malignancy of the oral tongue

Documentation placing the tumor in the anterior two-thirds (oral tongue) vs posterior third (base)

Provider query documented regarding specific surface involvement

Staging and treatment plan documented

MEAT Support

HCC Buddy guidance

Pathology confirming malignancy of the oral tongue

Documentation placing the tumor in the anterior two-thirds (oral tongue) vs posterior third (base)

Provider query documented regarding specific surface involvement

Staging and treatment plan documented

Audit Caution

HCC Buddy guidance

Accepting this code when pathology or operative reports specify the exact surface — always check surgical and pathology documentation

Confusing anterior two-thirds (oral tongue) with posterior third (base of tongue) — different cancer staging systems apply

Not querying the provider for surface specification when it would change the code

Using C02.9 (completely unspecified) when documentation at least confirms the anterior two-thirds

Common Mistakes

HCC Buddy guidance

C02.0 (Dorsal surface) - use when top surface is specified

C02.1 (Border of tongue) - use when lateral margin is specified

C02.2 (Ventral surface) - use when undersurface is specified

C01 (Base of tongue) - base is posterior third, not anterior two-thirds

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 C02.3 an HCC code?

Yes. C02.3 (Malignant neoplasm of anterior two-thirds of tongue, part unspecified) maps to HCC 21, Lymphoma and Other Cancers under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.671. 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: C02.3 is billable and maps to V28 HCC 21, Lymphoma and Other Cancers. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: C02.3
Description: Malignant neoplasm of anterior two-thirds of tongue, part unspecified
HCC (V28): HCC 21 — Lymphoma and Other Cancers
RAF reference coefficient: 0.671
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 21, Lymphoma and Other Cancers

0.671

ESRDHCC 11, Colorectal/Bladder/and Other Cancers

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 C02.3 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT Criteria for C02.3

For C02.3 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 C02.3 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

C02.3 is the ICD-10-CM diagnosis code for malignant neoplasm of anterior two-thirds of tongue, part unspecified. Cancer of the front two-thirds of the tongue when the exact surface location is not specified. C02.3 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of lip, oral cavity and pharynx (c00-c14).

Under the CMS-HCC V28 risk adjustment model, C02.3 maps to Lymphoma and Other Cancers (HCC 21) with a source-labeled community, non-dual, aged reference coefficient of 0.671. No V24 mapping is shown for C02.3; use the applicable model and payment year when reviewing the V28 mapping. 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. 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.

Use this code when documentation indicates anterior tongue but does not specify dorsal, ventral, or border. Because C02.3 maps to an HCC category, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) before the diagnosis is used for risk adjustment. 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 C02.3 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use this code when documentation indicates anterior tongue but does not specify dorsal, ventral, or border
•This is a less specific code; request clarification if the exact surface can be determined

Clinical Significance

Malignant neoplasm of anterior two-thirds of tongue, part unspecified, is used when documentation confirms cancer of the oral tongue but does not specify the exact surface (dorsal, ventral, or border). This less-specific code should prompt a documentation query, as the specific subsite affects surgical approach and prognosis.

Documentation Requirements

✓Pathology confirming malignancy of the oral tongue
✓Documentation placing the tumor in the anterior two-thirds (oral tongue) vs posterior third (base)
✓Provider query documented regarding specific surface involvement
✓Staging and treatment plan documented
✓Active malignancy confirmed

Commonly Confused Codes

•C02.0 (Dorsal surface) - use when top surface is specified
•C02.1 (Border of tongue) - use when lateral margin is specified
•C02.2 (Ventral surface) - use when undersurface is specified
•C01 (Base of tongue) - base is posterior third, not anterior two-thirds
•C02.9 (Tongue, unspecified) - even less specific; does not indicate anterior vs posterior