2026 ICD-10-CM Diagnosis Code H70.013Subperiosteal abscess of mastoid, bilateral

ICD-10-CM Codes›H60–H95›H65-H75›H70

ICD-10-CM H70.013
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

H70.013 is a billable ICD-10-CM diagnosis code for subperiosteal abscess of mastoid, bilateral. 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 abscess of left mastoid. 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
H70.013
Billable Status
Yes — Valid for Submission
Code Describes
Subperiosteal abscess of mastoid, bilateral
Short Description
Subperiosteal abscess of mastoid, bilateral
Same as the full description in the CMS dataset.
Parent Code
H70.01
Subperiosteal abscess of mastoid

Code Classification

ChapterH60–H95Diseases of the ear and mastoid process
SectionH65-H75Diseases of middle ear and mastoid
CategoryH70Mastoiditis and related conditions
This CodeH70.013Subperiosteal abscess of mastoid, bilateral

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abscess of left mastoid
  • Abscess of mastoid
  • Abscess of right mastoid
  • Abscess of temporal bone
  • Bilateral disorder of mastoids
  • Bilateral subperiosteal abscess of mastoids
  • Subperiosteal abscess of left mastoid
  • Subperiosteal abscess of mastoid
  • Subperiosteal abscess of right mastoid

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

Abscess

An abscess is a pocket of pus. You can get an abscess almost anywhere in your body. When an area of your body becomes infected, your body's immune system tries to fight the infection. White blood cells go to the infected area, collect within the damaged tissue, and cause inflammation. During this process, pus forms.

Read the full article at MedlinePlus

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

Convert H70.013 to ICD-9-CMHistory

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

ICD-9-CM
383.01 Subperi mastoid abscess
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 H70.013Overview

Is H70.013 (Subperiosteal abscess of mastoid) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report subperiosteal abscess of mastoid, bilateral on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does H70.013 group to?

When subperiosteal abscess of mastoid, bilateral 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 H70.013?

Under the General Equivalence Mappings, subperiosteal abscess of mastoid, bilateral converts to ICD-9-CM 383.01 (subperi mastoid abscess). 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.