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LCD L33977: Transcranial Doppler Studies

LCD L33977, Transcranial Doppler Studies, is the Local Coverage Determination that First Coast Service Options, Inc. applies to claims from 3 states (FL, PR, VI), effective 2019-10-29 and first in force 2015-10-01. The policy text runs 467 words, and its billing and coding article A57633 lists 160 ICD-10-CM codes that support medical necessity for 7 procedure codes. No other contractor publishes a policy with this title.

QuickIntell editorial content · Legacy registry date · Review not verified

Data effective
Data currency: Medicare Coverage Database LCD export release of September 24, 2026 (effective September 20, 2026). Next CMS release: weekly (Thursdays) for the MCD.
Contractor
First Coast Service Options, Inc.
States and territories
3
FL PR VI
Revision effective
2019-10-29
Original effective
2015-10-01
Policy text
467 words
Covered ICD-10 codes (articles)
160

Where this LCD applies

Each contract number is a jurisdiction on the remittance; the policy binds claims processed under these contracts and no others.

Contracts that apply LCD L33977
ContractContractorTypeStates
09102First Coast Service Options, Inc.A and B MACFL
09202First Coast Service Options, Inc.A and B MACPR
09302First Coast Service Options, Inc.A and B MACVI

Billing and coding: diagnoses and procedure codes

Since 2019 the codes live in the companion article rather than the LCD. Billing and Coding A57633 (Billing and Coding: Transcranial Doppler Studies) carries the diagnosis and procedure lists the contractor loads as the claims edit. CPT codes are shown as bare numbers because the descriptors are licensed by the AMA; HCPCS Level II descriptors are public and shown.

A57633: Billing and Coding: Transcranial Doppler Studies (Billing and Coding, effective 2025-01-01)

Covered ICD-10-CM codes
160
1 group
Non-covered ICD-10-CM codes
1
Procedure codes listed
7
Full article
cms.gov record
First 24 covered ICD-10-CM codes in A57633
ICD-10-CMDescription (FY2027)
G45.0—
G45.2—
G45.3—
G45.4—
G45.8—
G45.9—
G46.0—
G46.1—
G46.2—
G93.81—
G93.82—
G93.89—
G97.31—
G97.32—
G97.48—
G97.49—
G97.51—
G97.52—
I60.01—
I60.02—
I60.11—
I60.12—
I60.2—
I60.31—

Procedure codes: 93886, 93888, 93892, 93893, 93896, 93897, 93898.

Coverage indications, limitations and medical necessity

History/Background and/or General Information

Transcranial doppler uses low-frequency doppler transducers applied across the thin portions of the temporal bone (the temporal acoustic windows) to obtain flow velocity information from the basal intracerebral arteries. The transtemporal acoustic window provides access to hemodynamic data from the middle, anterior, and posterior cerebral arteries. A suboccipital approach, with insonation through the foramen magnum, provides access to the intracranial vertebral and basilar arteries, while a transorbital approach can be used to insonate the ophthalmic artery and the carotid siphon via the optic foramen. This data allows evaluation of the direction, depth, speed, and characteristics of flow in these vessels.

Covered Indications

Transcranial doppler evaluation of the intracranial cerebrovascular system will be considered medically necessary in any of the following circumstances:

• The patient has suspected severe intracranial arterial stenosis based on finite clinical evidence of focal ischemia, and knowledge of this stenosis is necessary in order to properly care for the patient.

• The patient has areas of known severe stenosis or occlusion of arteries supplying the brain and assessment of the pattern and extent of collateral circulation is necessary in order to properly care for the patient.

• The patient has suffered a subarachnoid hemorrhage and transcranial doppler studies are necessary to assess vasoconstriction of cerebral vessels.

• The patient has suspected or confirmed arteriovenous malformation, and an assessment of the arterial supply and flow pattern is necessary.

• The patient has suspected brain death.

Limitations

Headaches or dizziness are not indications for transcranial doppler studies of the intracranial vessels unless associated with other localizing signs and symptoms such as nystagmus, limb ataxia, etc.

Transcranial doppler studies performed to monitor cerebral vascular resistance and the effects of vasodilators and other drugs in the treatment of stroke and other brain damage is considered investigational, and therefore not covered.

The use of a simple hand-held or other Doppler device that does not produce hard copy output, or that produces a record that does not permit analysis of bidirectional vascular flow, is considered part of the physical examination of the vascular system and is not separately reported. The appropriate assignment of a specific ultrasound CPT code is not solely determined by the weight, size, or portability of the equipment, but rather by the extent, quality, and documentation of the procedure. If an examination is performed with hand-carried equipment, the quality of the exam, printout, and report must be in keeping with accepted national standards.

As published in the CMS IOM Publication 100-08, Medicare Program Integrity Manual , Chapter 13, Section 13.5.4, an item or service may be covered by a contractor LCD if it is reasonable and necessary under the Social Security Act Section 1862 (a)(1)(A). Contractors shall determine and describe the circumstances under which the item or service is considered reasonable and necessary.

Summary of evidence (opening)

N/A

the full summary and analysis of evidence are in the CMS record.

Dates, lineage and related policies

Original determination effective
2015-10-01
Current revision effective
2019-10-29
Last reviewed by the contractor
2018-04-25
MCD version
18
Derived from
L29293

The contractor lists 3 National Coverage Determinations as related: NCD 20.14 Plethysmography, NCD 20.17 Noninvasive Tests of Carotid Function, NCD 220.5 Ultrasound Diagnostic Procedures. Where an NCD speaks, it controls; the LCD can only address what the NCD leaves open.

Using this policy on a claim

Match the documented indication to the covered indications above before the service is scheduled, carry a diagnosis from the article's covered list on the claim line, and keep the elements the documentation section asks for in the record, because the contractor can request it later through medical review. A denial under this policy arrives as CARC 50 with remark N115; the LCD lookup guide walks through the appeal path and the Advance Beneficiary Notice rules, and the First Coast Service Options, Inc. hub lists every other active policy from the same contractor.

Frequently asked questions

What does LCD L33977 cover?

Transcranial doppler uses low-frequency doppler transducers applied across the thin portions of the temporal bone (the temporal acoustic windows) to obtain flow velocity information from the basal intracerebral arteries. The transtemporal acoustic window provides access to hemodynamic data from the middle, anterior, and posterior cerebral arteries. A suboccipital approach, with insonation through the foramen… The full indications and limitations are reproduced on this page from the CMS Medicare Coverage Database export of September 24, 2026.

Which states does LCD L33977 apply to?

First Coast Service Options, Inc. applies it to Medicare claims in FL, PR, VI. A Local Coverage Determination binds only the contractor that wrote it; the same service in another jurisdiction is judged under that contractor's own policy or, where none exists, claim by claim.

Which diagnosis codes support medical necessity under LCD L33977?

The companion billing and coding article A57633 lists 160 ICD-10-CM codes in 1 group that support medical necessity and 1 that do not; the first 24 appear on this page and the complete list is in the article on cms.gov.

How do I appeal a denial under LCD L33977?

The remittance carries claim adjustment reason code 50 with remark code N115, naming the LCD. Compare the documented indication with the policy's covered indications and the article's diagnosis list, then file a redetermination within 120 days with the record attached; if the service genuinely falls outside the policy, the patient can be billed only when a valid Advance Beneficiary Notice was obtained before the service.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-02. Verify against the primary file before billing or contracting decisions.

Disclaimer

The policy text and code lists are reproduced from the CMS Medicare Coverage Database export as an operational reference. Verify against the current LCD and article on cms.gov before billing; coverage depends on the full record and the contractor. Not legal, clinical or billing advice.