What is ICD-10 code C30.1?

C30.1 is the ICD-10-CM diagnosis code for Malignant neoplasm of middle ear. Cancer of the middle ear, the air-filled space behind the eardrum that contains tiny bones for hearing. It belongs to the ICD-10-CM chapter for neoplasms (c00-d49). C30.1 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C30.1 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. C30.1 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. C30.1 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 C30.1 map to under V28?

C30.1 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 C30.1: Malignant neoplasm of middle

C30.1 maps to CMS-HCC V28 21. 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

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Code lookupC30.1

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of respiratory and intrathoracic organs (C30-C39)

C30.1

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

Malignant neoplasm of middle ear

Cancer of the middle ear, the air-filled space behind the eardrum that contains tiny bones for hearing.

Buddy Insight

Middle ear cancer is extremely rare, and most middle ear malignancies are squamous cell carcinomas often associated with chronic otitis media.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

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

C30Malignant neoplasm of nasal cavity and middle ear C30.1Malignant neoplasm of middle ear

Inclusion Terms

Official

Malignant neoplasm of antrum tympanicum
Malignant neoplasm of auditory tube
Malignant neoplasm of eustachian tube
Malignant neoplasm of inner ear
Malignant neoplasm of mastoid air cells
Malignant neoplasm of tympanic cavity

Excludes 2

Official

No Excludes 2 notes are included in this display for C30.1. Check the code and parent instructions in the Code Book.

Related Codes

Official

C30.0Malignant neoplasm of nasal cavity

Includes

Official

malignant neoplasm of middle earInherited from C30-C39

Excludes 1

Official

malignant neoplasm of auricular canal (external) (C43.2-,C44.2-)
malignant neoplasm of bone of ear (meatus) (C41.0)
malignant neoplasm of cartilage of ear (C49.0)
malignant melanoma of skin of (external) ear (C43.2-)
other and unspecified malignant neoplasm of skin of (external) ear (C44.2-)
mesothelioma (C45.-)Inherited from C30-C39

Code First

Official

No Code First sequencing instructions are included in this display for C30.1. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for C30.1. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for C30.1. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Pathology confirmation of primary middle ear malignancy

Imaging (CT/MRI temporal bone) documenting tumor extent

Verification that the tumor is primary to the middle ear, not metastatic

Documentation of any extension into mastoid, inner ear, or intracranial structures

MEAT Support

HCC Buddy guidance

Pathology confirmation of primary middle ear malignancy

Imaging (CT/MRI temporal bone) documenting tumor extent

Verification that the tumor is primary to the middle ear, not metastatic

Documentation of any extension into mastoid, inner ear, or intracranial structures

Audit Caution

HCC Buddy guidance

Failing to verify that the cancer is primary to the middle ear rather than secondary from adjacent sites

Confusing middle ear cancer with external ear (pinna) cancer which uses skin neoplasm codes

Not documenting temporal bone invasion which affects staging and treatment

Using this code for benign middle ear tumors like paragangliomas without malignant transformation

Common Mistakes

HCC Buddy guidance

C44.21 — Malignant neoplasm of skin of ear: External ear cancers use skin codes; middle ear is internal

C30.0 — Nasal cavity cancer: The middle ear communicates with the nasopharynx via the Eustachian tube; ensure correct site

C41.0 — Malignant neoplasm of bones of skull and face: Temporal bone invasion may be coded separately

H71 — Cholesteatoma of middle ear: Not malignant but can be locally destructive and confused with cancer on imaging

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 C30.1 an HCC code?

Yes. C30.1 (Malignant neoplasm of middle ear) 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: C30.1 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: C30.1
Description: Malignant neoplasm of middle ear
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 C30.1 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for C30.1

For C30.1, 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

C30.1 is the ICD-10-CM diagnosis code for malignant neoplasm of middle ear. Cancer of the middle ear, the air-filled space behind the eardrum that contains tiny bones for hearing. C30.1 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of respiratory and intrathoracic organs (c30-c39).

Under the CMS-HCC V28 risk adjustment model, C30.1 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 C30.1; use the applicable model and payment year when reviewing the V28 mapping. 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.

Middle ear cancer is rare; verify diagnosis carefully and ensure it is not metastatic disease from another site. For C30.1, 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 C30.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Middle ear cancer is rare; verify diagnosis carefully and ensure it is not metastatic disease from another site
•Document whether the cancer involves the mastoid bone or extends beyond the middle ear

Clinical Significance

Middle ear cancer is extremely rare, and most middle ear malignancies are squamous cell carcinomas often associated with chronic otitis media. Due to its rarity, this diagnosis requires careful verification to ensure it is not metastatic disease from another site. These tumors are aggressive and frequently involve the temporal bone, requiring complex surgical management.

Documentation Requirements

✓Pathology confirmation of primary middle ear malignancy
✓Imaging (CT/MRI temporal bone) documenting tumor extent
✓Verification that the tumor is primary to the middle ear, not metastatic
✓Documentation of any extension into mastoid, inner ear, or intracranial structures
✓Treatment plan and stage

Excludes 1, Do NOT code together

malignant neoplasm of auricular canal (external) (C43.2-,C44.2-)
malignant neoplasm of bone of ear (meatus) (C41.0)
malignant neoplasm of cartilage of ear (C49.0)
malignant melanoma of skin of (external) ear (C43.2-)
other and unspecified malignant neoplasm of skin of (external) ear (C44.2-)

Commonly Confused Codes

•C44.21: Malignant neoplasm of skin of ear: External ear cancers use skin codes; middle ear is internal
•C30.0: Nasal cavity cancer: The middle ear communicates with the nasopharynx via the Eustachian tube; ensure correct site
•C41.0: Malignant neoplasm of bones of skull and face: Temporal bone invasion may be coded separately
•H71: Cholesteatoma of middle ear: Not malignant but can be locally destructive and confused with cancer on imaging