2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 152 through 153, 791, 793. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 76 closely related codes. 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to H70.013: its own notes plus those printed at 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 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.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name H70.013, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming H70.013: its condition is not part of those codes, and both may be reported when the patient has both.

  • H74 Other disorders of middle ear mastoid
    mastoiditis (H70.-) names H70.-, which includes this code

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About H70.013Overview

What is the ICD-10 code for subperiosteal abscess of mastoid, bilateral?

The ICD-10-CM code for subperiosteal abscess of mastoid, bilateral is H70.013 (sometimes written as H70013). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

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 793, 791, 152, 153, with relative weights from 0.7420 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.

Is H70.013 a CC or MCC?

CMS lists H70.013 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 76 closely related codes in its exclusion list.

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.