Does A81.9 require prior authorization?

No, A81.9 does not require prior authorization (high confidence). Covered without prior authorization.

`A81.9`, Atypical virus infection of central nervous system, unspecified

ICD-10-CM

No Prior Auth Required

Covered without prior authorization (high confidence)

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.
Medical records must include history and physical notes, laboratory results, and documentation of signs and symptoms that warrant the head/neck diagnostic imaging.
Accurate HCPCS/CPT coding must be submitted to differentiate CT and MRI scans from other radiology services and to support coverage determinations.
Documentation and supporting information must be available to Medicare upon request.

CT or MRI scans of the head or neck are covered when the medical record documents the scan is reasonable and necessary for diagnostic evaluation.
Coverage requires documentation supporting clinical indication such as history and physical exam findings, laboratory results, and signs or symptoms that justify the diagnostic test.
ICD-10 codes covered if selection criteria are met (not all-inclusive): F02.80: Dementia in other diseases classified elsewhere, without behavioral disturbance
ICD-10 codes covered if selection criteria are met (not all-inclusive): F02.A0, F02.B0, F02.C0, F02.C4: Dementia in other diseases classified elsewhere, with behavioral disturbance
ICD-10 codes covered if selection criteria are met (not all-inclusive): F03.90 - F03.C4: Unspecified dementia
ICD-10 codes covered if selection criteria are met (not all-inclusive): F06.1, F06.8: Psychotic disorders with hallucinations and other specified mental disorders due to known physiological conditions

AETNA-CPB-0221, Quantitative EEG (Brain Mapping)

A56612, Billing and Coding: CT of the Head

A57204, Billing and Coding: MRI and CT Scans of the Head and Neck

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