---
title: "ICD-10-CM R94.121: Abnormal vestibular function study | BillingBrief"
description: "ICD-10-CM code R94.121: Abnormal vestibular function study. Category, related codes, and the official source, in plain English."
canonical: "https://billingbrief.com/icd10/r94.121/"
language: "en"
---

# R94.121 Abnormal vestibular function study

ICD-10-CM · [CMS code reference](#source)

**Official ICD-10-CM description:** Abnormal vestibular function study

## Related codes

-   [`R94.01` Abnormal electroencephalogram \[EEG\] ICD-10-CM](https://billingbrief.com/icd10/r94.01/)
-   [`R94.02` Abnormal brain scan ICD-10-CM](https://billingbrief.com/icd10/r94.02/)
-   [`R94.09` Abnormal results of other function studies of central nervous system ICD-10-CM](https://billingbrief.com/icd10/r94.09/)
-   [`R94.110` Abnormal electro-oculogram \[EOG\] ICD-10-CM](https://billingbrief.com/icd10/r94.110/)
-   [`R94.111` Abnormal electroretinogram \[ERG\] ICD-10-CM](https://billingbrief.com/icd10/r94.111/)
-   [`R94.112` Abnormal visually evoked potential \[VEP\] ICD-10-CM](https://billingbrief.com/icd10/r94.112/)
-   [`R94.113` Abnormal oculomotor study ICD-10-CM](https://billingbrief.com/icd10/r94.113/)
-   [`R94.118` Abnormal results of other function studies of eye ICD-10-CM](https://billingbrief.com/icd10/r94.118/)

## Common questions

### Is R94.121 a billable code?

Yes. R94.121 is a billable ICD-10-CM code in the ICD-10-CM FY2027 (effective October 1, 2026) code set.

## From the source

Official description from [CMS](https://www.cms.gov/medicare/coding-billing/icd-10-codes).
ICD-10-CM FY2027 (effective October 1, 2026).

Code set

ICD-10-CM

Category

R94 Abnormal results of function studies

Chapter

Symptoms, signs and abnormal clinical and laboratory findings

Billable

Yes

Educational reference only. Not medical, legal, or billing advice. Always check the current official code set and payer policy before you bill. [About BillingBrief and our sources](https://billingbrief.com/about/).