2026 ICD-10-CM Diagnosis Code H70.209Unspecified petrositis, unspecified ear

ICD-10-CM Codes›H60–H95›H65-H75›H70

ICD-10-CM H70.209
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

H70.209 is a billable ICD-10-CM diagnosis code for unspecified petrositis, unspecified ear. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 152 through 153. Coders also document this condition as coalescing osteitis of petrous bone. 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
H70.209
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified petrositis, unspecified ear
Short Description
Unspecified petrositis, unspecified ear
Same as the full description in the CMS dataset.
Parent Code
H70.20
Unspecified petrositis

Code Classification

ChapterH60–H95Diseases of the ear and mastoid process
SectionH65-H75Diseases of middle ear and mastoid
CategoryH70Mastoiditis and related conditions
This CodeH70.209Unspecified petrositis, unspecified ear

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Coalescing osteitis of petrous bone
  • Cranial neuropathy due to petrous infection
  • Osteomyelitis of petrous bone
  • Osteomyelitis of temporal bone
  • Petrositis
  • Petrous apicitis

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

Clinical InformationClinical

  • Petrositis

    inflammation of petrous bone.

  • Petrous Bone

    the dense rock-like part of temporal bone that contains the inner ear. petrous bone is located at the base of the skull. sometimes it is combined with the mastoid process and called petromastoid part of temporal bone.

Patient EducationClinical

Ear Infections

Ear infections are the most common reason parents bring their child to a doctor. Three out of four children will have at least one ear infection by their third birthday. Adults can also get ear infections, but they are less common.

Read the full article at MedlinePlus

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

Convert H70.209 to ICD-9-CMHistory

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

ICD-9-CM
383.20 Petrositis NOS
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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About H70.209Overview

Is H70.209 (Unspecified petrositis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified petrositis, unspecified ear on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does H70.209 group to?

When unspecified petrositis, unspecified ear is the principal diagnosis on an inpatient stay, it groups to MS-DRG 152, 153, with relative weights from 0.7382 to 1.1822 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of H70.209?

Under the General Equivalence Mappings, unspecified petrositis, unspecified ear converts to ICD-9-CM 383.20 (petrositis NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.