2026 ICD-10-CM Diagnosis Code C30.1Malignant neoplasm of middle ear
ICD-10-CM Codes›C00–D49›C30-C39›C30
- Billable — Valid for Submission
- Risk Adjusts — HCC 21
- Chronic Condition
C30.1 is a billable ICD-10-CM diagnosis code for malignant neoplasm of middle ear. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 11 through 13, 146 through 148. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Head and neck cancers - all other types.
For Medicare Advantage risk adjustment, C30.1 maps to CMS-HCC Category 21 (Lymphoma and Other Cancers) under the V28 model, adding a risk factor of about 0.671 for a community, non-dual, aged beneficiary in payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
C30.1 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Malignant middle ear paraganglioma
- Malignant neoplasm of auditory tube, middle ear and mastoid air cells
- Malignant neoplasm of eustachian tube
- Malignant neoplasm of mastoid
- Malignant neoplasm of mastoid air cells
- Malignant neoplasm of mastoid antrum
- Malignant neoplasm of middle ear
- Malignant neoplasm of middle ear and mastoid
- Malignant neoplasm of nasal cavities, middle ear and accessory sinuses
- Malignant neoplasm of opening of auditory tube
- Malignant neoplasm of tympanic cavity
- Mass of petrous part of temporal bone
- Neoplasm of eustachian tube
- Neoplasm of mastoid air cells
- Neoplasm of mastoid antrum
- Neoplasm of middle ear and mastoid
- Neoplasm of ostium of eustachian tube
- Neoplasm of tympanic cavity
- Primary adenocarcinoma of middle ear
- Primary malignant middle ear paraganglioma
- Primary malignant neoplasm of eustachian tube
- Primary malignant neoplasm of mastoid air cells
- Primary malignant neoplasm of middle ear
- Primary malignant neoplasm of temporal bone
- Primary squamous cell carcinoma of ear
- Primary squamous cell carcinoma of middle ear
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- 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
Type 1 Excludes
- 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
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Eustachian Tube
a narrow passageway that connects the upper part of the throat to the tympanic cavity.
Table of NeoplasmsClinical
Anatomical sites in the Table of Neoplasms that reference this code family.
| Site | Malig. Primary | Malig. Secondary | Ca in situ | Benign | Uncertain | Unspec. |
|---|---|---|---|---|---|---|
| antrum (Highmore) (maxillary) › tympanicum | C30.1 | C78.39 | D02.3 | D14.0 | D38.5 | D49.1 |
| auditory › canal (external) (skin) › internal | C30.1 | C78.39 | D02.3 | D14.0 | D38.5 | D49.1 |
| auditory › tube | C30.1 | C78.39 | D02.3 | D14.0 | D38.5 | D49.1 |
| auricular canal (external) [See Also: Neoplasm, skin, ear] › internal | C30.1 | C78.39 | D02.3 | D14.0 | D38.5 | D49.2 |
| cavity › tympanic | C30.1 | C78.39 | D02.3 | D14.0 | D38.5 | D49.1 |
| ear (external) [See Also: Neoplasm, skin, ear] › inner | C30.1 | C78.39 | D02.3 | D14.0 | D38.5 | D49.1 |
| ear (external) [See Also: Neoplasm, skin, ear] › middle | C30.1 | C78.39 | D02.3 | D14.0 | D38.5 | D49.1 |
| eustachian tube | C30.1 | C78.39 | D02.3 | D14.0 | D38.5 | D49.1 |
| mastoid (air cells) (antrum) (cavity) | C30.1 | C78.39 | D02.3 | D14.0 | D38.5 | D49.1 |
| tympanic cavity | C30.1 | C78.39 | D02.3 | D14.0 | D38.5 | D49.1 |
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Convert C30.1 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C30.1Overview
What is the ICD-10 code for malignant neoplasm of middle ear?
The ICD-10-CM code for malignant neoplasm of middle ear is C30.1 (sometimes written as C301). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is C30.1 (Malignant neoplasm of nasal cavity and middle ear) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of middle ear on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does C30.1 group to?
When malignant neoplasm of middle ear is the principal diagnosis on an inpatient stay, it groups to MS-DRG 11, 12, 13, 146, 147, 148, with relative weights from 0.7971 to 5.4541 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of C30.1?
Under the General Equivalence Mappings, malignant neoplasm of middle ear converts to ICD-9-CM 160.1 (malig neo middle ear). The mapping is a direct match.
What HCC is C30.1?
C30.1 (malignant neoplasm of middle ear) maps to CMS-HCC Category 21 (Lymphoma and Other Cancers), commonly written as HCC 21, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 11 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 22.
Does C30.1 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, C30.1 adds a risk adjustment factor of about 0.671 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.493 to 0.739 depending on the payment segment). A more severe related category (HCC 17, HCC 18, HCC 19, and HCC 20) supersedes it when both are reported. See the full factor table on the HCC 21 category page.
