H70.1 – Chronic mastoiditis
ICD-10-CM 2027 diagnosis code · Diseases of middle ear and mastoid
ICD-10-CM code
H70.1
- Code
H70.1(claims format:H701)- Description
- Chronic mastoiditis
- Billable
- No – use a more specific code below
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 8. Diseases of the ear and mastoid process (H60-H95)
- Block
- H65-H75 Diseases of middle ear and mastoid
- Parent codes
- H70
Billable codes under H70.1
H70.1 is a header code and cannot be used on claims. Choose the most specific code:
Notes for H70.1
Applicable to:
- Caries of mastoid
- Fistula of mastoid
Excludes1 (not coded here):
- tuberculous mastoiditis (A18.03)
Index terms for H70.1
Entries in the ICD-10-CM alphabetic index that lead to this code:
Related codes in H70
Frequently asked questions
What is ICD-10 code H70.1?
H70.1 is the ICD-10-CM code for chronic mastoiditis, in the block H65-H75 (Diseases of middle ear and mastoid).
Is H70.1 a billable code?
No. H70.1 is a header code with more specific child codes; report one of the billable codes listed above.
What category does H70.1 belong to?
It belongs to category H70 – Mastoiditis and related conditions.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.