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ICD-10-CM 2027 diagnosis code

H70.01Subperiosteal abscess of mastoid

Not billable — use a more specific code

H70.01 is a header code, so it can't be reported by itself. Choose one of the 4 more specific codes beneath it.

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 H70.01

H70.01 is the ICD-10-CM diagnosis code for Subperiosteal abscess of mastoid. It belongs to category H70 (mastoiditis and related conditions), block H65-H75 (diseases of middle ear and mastoid) and chapter 8 (diseases of the ear and mastoid process). It is a header code, so it can't be reported by itself; one of its 4 subcodes must be used instead.

Within H70.0 (acute mastoiditis), H70.01 is specifically for Subperiosteal abscess of mastoid. Related codes cover without complications (H70.00) and with other complications (H70.09).

To report this condition, pick the subcode that matches the documentation: H70.011 (right ear), H70.012 (left ear), H70.013 (bilateral) and H70.019 (unspecified ear).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under H70.01

Notes that apply from higher levels

Instructions written at a parent level also apply to H70.01.

Broader instructions also apply from Chapter 8: Diseases of the ear and mastoid process.

Alphabetic index entries

1 entries

Terms in the official ICD-10-CM index that lead to H70.01.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about H70.01

Is H70.01 billable?

No. H70.01 is a header code. Report one of its more specific subcodes instead.