G91.1 – Obstructive hydrocephalus
ICD-10-CM 2027 diagnosis code · Other disorders of the nervous system
ICD-10-CM code
G91.1
- Code
G91.1(claims format:G911)- Description
- Obstructive hydrocephalus
- Billable
- Yes – valid for HIPAA-covered transactions
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 6. Diseases of the nervous system (G00-G99)
- Block
- G89-G99 Other disorders of the nervous system
- Parent codes
- G91
Notes inherited from parent codes
Instructional notes at a category or block level apply to every code below it.
G91 – Hydrocephalus
Includes:
- acquired hydrocephalus
Index terms for G91.1
Entries in the ICD-10-CM alphabetic index that lead to this code:
- Hydrocephalus, obstructive
- Occlusion, occluded, ventricle
- Hydrocephalus, noncommunicating
- Block, blocked, foramen Magendie
- Hydrocephalus, foramen Magendie block
- Occlusion, occluded, aqueduct of Sylvius
- Stricture, aqueduct of Sylvius, acquired
- Stenosis, stenotic, aqueduct of Sylvius, acquired
- Obstruction, obstructed, obstructive, aqueduct of Sylvius
Related codes in G91
Frequently asked questions
What is ICD-10 code G91.1?
G91.1 is the ICD-10-CM code for obstructive hydrocephalus, in the block G89-G99 (Other disorders of the nervous system).
Is G91.1 a billable code?
Yes. G91.1 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.
What category does G91.1 belong to?
It belongs to category G91 – Hydrocephalus.
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.