2027 ICD-10-CM Diagnosis Code H74.312Ankylosis of ear ossicles, left ear

ICD-10-CM Codes›H60–H95›H65-H75›H74

ICD-10-CM H74.312
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

H74.312 is a billable ICD-10-CM diagnosis code for ankylosis of ear ossicles, left ear. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 154 through 156. Coders also document this condition as ankylosis of ossicles of left ear. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Diseases of middle ear and mastoid (except otitis media).

Code Identity

ICD-10-CM Code
H74.312
Billable Status
Yes — Valid for Submission
Code Describes
Ankylosis of ear ossicles, left ear
Short Description
Ankylosis of ear ossicles, left ear
Same as the full description in the CMS dataset.
Parent Code
H74.31
Ankylosis of ear ossicles

Code Classification

ChapterH60–H95Diseases of the ear and mastoid process
SectionH65-H75Diseases of middle ear and mastoid
CategoryH74Other disorders of middle ear mastoid
This CodeH74.312Ankylosis of ear ossicles, left ear

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Ankylosis of ossicles of left ear
  • Ossicular ankylosis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to H74.312: its own notes plus those printed at H74 and Chapter 8. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From H74 Other disorders of middle ear mastoid applies to 36 codes
From Chapter 8 (H60-H95) Diseases of the ear and mastoid process applies to 653 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Notes

General instructions on how these codes are used.

From Chapter 8 (H60-H95) Diseases of the ear and mastoid process applies to 653 codes
  • Use an external cause code following the code for the ear condition, if applicable, to identify the cause of the ear condition

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR EAR002
Diseases of middle ear and mastoid (except otitis media)
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Ear Disorders

An ear disorder is any condition that changes or harms the shape or structure of your ear. This can include abnormal ear shapes you're born with, injuries that change your ear's shape, and a growth on or in the ear.

The full article covers:

  • What is an ear disorder?
  • What causes ear disorders?
  • What are the symptoms of ear disorders?
  • How are ear disorders diagnosed?
  • How are ear disorders treated?
  • Can ear disorders be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert H74.312 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
385.21 Ankylosis malleus
Approximate The match is approximate rather than exact.
ICD-9-CM
385.22 Ankylosis ear ossicl NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About H74.312Overview

What is the ICD-10 code for ankylosis of ear ossicles, left ear?

The ICD-10-CM code for ankylosis of ear ossicles, left ear is H74.312 (sometimes written as H74312). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is H74.312 (Ankylosis of ear ossicles) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report ankylosis of ear ossicles, left ear on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does H74.312 group to?

When ankylosis of ear ossicles, left ear is the principal diagnosis on an inpatient stay, it groups to MS-DRG 156, 155, 154, with relative weights from 0.6656 to 1.5916 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of H74.312?

Under the General Equivalence Mappings, ankylosis of ear ossicles, left ear converts to ICD-9-CM 385.21 (ankylosis malleus) and 385.22 (ankylosis ear ossicl NEC). The mapping is approximate, so confirm the match fits the documentation.