ICD-10-CM 2027 diagnosis code
C30.1Malignant neoplasm of middle ear
C30.1 is a valid, billable ICD-10-CM code for malignant neoplasm of middle ear. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About C30.1
C30.1 is the ICD-10-CM diagnosis code for malignant neoplasm of middle ear. It belongs to category C30 (malignant neoplasm of nasal cavity and middle ear), block C30-C39 (malignant neoplasms of respiratory and intrathoracic organs) and chapter 2 (neoplasms). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within C30 (malignant neoplasm of nasal cavity and middle ear), C30.1 is specifically for malignant neoplasm of middle ear. Related codes cover nasal cavity (C30.0).
Don't report C30.1 together with the conditions in its Excludes1 note: 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-) and 1 more.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC, relative weight 5.6154), DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC, relative weight 4.381), DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC, relative weight 2.7307), DRG 146 (Ear, Nose, Mouth and Throat Malignancy with MCC, relative weight 2.1329), DRG 147 (Ear, Nose, Mouth and Throat Malignancy with CC, relative weight 1.3055) and DRG 148 (Ear, Nose, Mouth and Throat Malignancy without CC/MCC, relative weight 0.8008), in Pre-MDC and MDC 03 (Diseases and Disorders of the Ear, Nose, Mouth and Throat), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 160.1 (malignant neoplasm of auditory tube, middle ear, and mastoid air cells).
Coding notes
- 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
Notes that apply from higher levels
Instructions written at a parent level also apply to C30.1.
Broader instructions also apply from C30-C39 Malignant neoplasms of respiratory and intrathoracic organs and Chapter 2: Neoplasms.
Table of Drugs & Neoplasms entries
- Neoplasm, neoplastic › antrum (Highmore) (maxillary) › tympanicum — Malignant Primary
- Neoplasm, neoplastic › auditory › canal (external) (skin) › internal — Malignant Primary
- Neoplasm, neoplastic › auditory › tube — Malignant Primary
- Neoplasm, neoplastic › auricular canal (external) › internal — Malignant Primary
- Neoplasm, neoplastic › cavity › tympanic — Malignant Primary
- Neoplasm, neoplastic › ear (external) › inner — Malignant Primary
- Neoplasm, neoplastic › ear (external) › middle — Malignant Primary
- Neoplasm, neoplastic › eustachian tube — Malignant Primary
- Neoplasm, neoplastic › mastoid (air cells) (antrum) (cavity) — Malignant Primary
- Neoplasm, neoplastic › tympanic cavity — Malignant Primary
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC PRE · Pre-MDC
MDC 03 · Diseases and Disorders of the Ear, Nose, Mouth and Throat
ICD-9-CM equivalent
Converter →- 160.1Malignant neoplasm of auditory tube, middle ear, and mastoid air cellsexact
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about C30.1
Is C30.1 billable?
- Yes. C30.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can C30.1 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict C30.1 as a principal diagnosis.
Is C30.1 a CC or MCC?
- No. C30.1 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does C30.1 group to?
- C30.1 is used in the MS-DRG v44.0 logic for MS-DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC), MS-DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC), MS-DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC), MS-DRG 146 (Ear, Nose, Mouth and Throat Malignancy with MCC), MS-DRG 147 (Ear, Nose, Mouth and Throat Malignancy with CC) and MS-DRG 148 (Ear, Nose, Mouth and Throat Malignancy without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for C30.1?
- The CMS General Equivalence Mappings map C30.1 to ICD-9-CM 160.1.