CPT code 92538: Caloric vestibular test, unilateral, with recording2026 Medicare rate & RVUs

Medicare pays $21.71 for 92538 nationally in the office. Local office rates run $19.79–$27.49.

Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.

What 92538 covers

This test stimulates the vestibular system by introducing warm or cool air or water into the ear canal, then records the resulting eye movements, including nystagmus. Audiologists and physicians such as otolaryngologists may perform or interpret it in an audiology, ENT, or balance-testing setting. It is used as part of a diagnostic evaluation when symptoms or findings suggest impaired vestibular function.

Choose 92538 when recorded caloric testing is performed on one side; 92537 is the bilateral recorded-test sibling. Documentation should identify the ear tested, the stimulation performed, the recorded response, and the interpretation when applicable. The global service includes the professional interpretation and the technical work, equipment, and staff. Modifier 26 reports the interpretation alone, while modifier TC reports the technical portion alone. CMS pricing treats this code as already priced bilaterally, so modifier 50 does not increase payment.

This summary was written with AI assistance from CMS physician fee schedule data and checked against the CMS billing rules shown here. Rates on this page come directly from CMS files.

Where 92538 pays more and less

The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.

109 of 109 payment localities

92538 rates by state

Office rate range in each state. Select a state to see its payment localities.

How the 92538 rate is calculated

Each of 92538’s three RVUs is multiplied by a geographic index (GPCI) for the payment locality, added up, and multiplied by the conversion factor. Drag the indexes or enter a ZIP to see what moves the rate.

Payment rules and modifiers for 92538

The CMS indicators that decide how 92538 is paid alongside other services.

What modifiers do to the payment

When to use modifier 26

92538 compared with similar codes

How to choose

92537Caloric testWith eye-movement recording

92538 is for recorded caloric testing on one side; 92537 is the bilateral recorded-test code.

92533Caloric vestibular testEach irrigation

92533 is caloric vestibular testing without recording. Choose 92538 when the test includes recording.

92540Vestibular evaluationBasic test battery

92540 is a basic vestibular evaluation, not the specific recorded caloric stimulus and response reported with 92538.

92532Positional nystagmusWithout recording

92532 evaluates positional nystagmus; 92538 records the vestibular response to caloric stimulation.

Codes related to 92538

Related codes aren’t interchangeable: bill the code that matches the service performed.

Where these rates come from

FeeBase calculates base physician payments from CMS work, practice-expense and malpractice RVUs, adjusted by each locality’s geographic indexes and the conversion factor. Services without a published rate are labeled, never given a made-up amount. Amounts are Medicare allowed amounts before claim adjustments: not a patient’s bill or a commercial rate.

CMS RVU26D · effective Oct 1, 2026 through the day before Jan 1, 2027

Open CMS sourceHow we calculate rates