Does G93.89 require prior authorization?

No, G93.89 does not require prior authorization (high confidence). Code is covered without prior authorization.

`G93.89` — Other specified disorders of brain

ICD-10-CM

No Prior Auth Required

Code is covered without prior authorization (high confidence)

When billing these procedures after carotid endarterectomy, include the surgery date and the phrase 'carotid endarterectomy' in the claim narrative.
When reporting a reduced (unilateral/limited) service, append modifier -52 and include an explanation of the reduced service in Item 19 of the CMS-1500 form or electronic equivalent; any appropriate supporting documentation may be submitted with the claim.
Follow Novitas LCD L35397 for the reasonable and necessary documentation requirements and frequency limitations, and consult NCCI edits for correct coding combinations prior to billing Medicare.
This article provides billing/coding guidelines that complement Local Coverage Determination L34417 for CT of the head; consult LCD L34417 for specific coverage, coding, and documentation requirements.

Non-invasive cerebrovascular arterial studies are covered when reasonable and necessary as defined by Novitas Local Coverage Determination (LCD) L35397.
Duplex post-interventional follow-up studies (typically limited and unilateral) are covered for evaluation after cerebrovascular intervention.
Vascular studies performed after carotid endarterectomy are covered when the claim includes the procedure date and the narrative 'carotid endarterectomy.'
Non-invasive vascular diagnostic tests are covered when ordered by the treating practitioner or a consulting physician who will use the results to manage the beneficiary's specific medical problem.
A documented referral/order must be on record for each individual non-invasive vascular study performed for coverage to apply.
Cerebrovascular arterial duplex follow-up is covered annually for stenosis 20–49% (diameter reduction).

L35397 — Non-Invasive Cerebrovascular Arterial Studies

J12

A52992 — Billing and Coding: Non-Invasive Cerebrovascular Arterial Studies

J12

A59845 — Billing and Coding: Magnetic Resonance Angiography

A59920 — Billing and Coding: Non-Invasive Vascular Studies

AETNA-CPB-0289 — Grid Monitoring and Intraoperative Electroencephalography

Ask Verity about documentation requirements, denial risks, or coverage in your state.