Where this LCD applies
Each contract number is a jurisdiction on the remittance; the policy binds claims processed under these contracts and no others.
Billing and coding: diagnoses and procedure codes
Since 2019 the codes live in the companion article rather than the LCD. Billing and Coding A57512 (Billing and Coding: Magnetic-Resonance-Guided Focused Ultrasound Surgery (MRgFUS) for Essential Tremor and Tremor Dominant Parkinson's Disease) 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.
A57512: Billing and Coding: Magnetic-Resonance-Guided Focused Ultrasound Surgery (MRgFUS) for Essential Tremor and Tremor Dominant Parkinson's Disease (Billing and Coding, effective 2025-09-11)
- Covered ICD-10-CM codes
- 6
- 1 group
- Non-covered ICD-10-CM codes
- 1
- Procedure codes listed
- 1
- Full article
- cms.gov record
| ICD-10-CM | Description (FY2027) |
|---|---|
| G20.A1 | — |
| G20.A2 | — |
| G20.B1 | — |
| G20.B2 | — |
| G20.C | — |
| G25.0 | — |
Procedure codes: 61715.
Coverage indications, limitations and medical necessity
This LCD addresses use of Magnetic-Resonance-Guided Focused Ultrasound Surgery (MRgFUS) for the treatment of idiopathic essential tremor (ET) patients including Tremor Dominant Parkinson's disease (TDPD) patients with medication-refractory tremor.
MRgFUS unilateral thalamotomy is considered medically reasonable and necessary in patients with all four of the following criteria:
medication refractory ET (defined as refractory to at least two trials of medical therapy, including at least one first-line agent)
moderate to severe postural or intention tremor of the dominant hand or another nationally accepted clinical measure of tremor severity
disabling ET (defined by a score of ≥2 on any of the eight items in the disability subsection of the CRST or another nationally accepted clinical measure of tremor severity)
not a candidate for DBS (e.g., advanced age, anticoagulant therapy, surgical comorbidities, or has failed Deep Brain Stimulation (DBS), but has no retained cranial implants)
Limitations (not covered):
• Treatment of head or voice tremor
• Bilateral thalamotomy
• An advanced neurodegenerative condition
• Unstable cardiac disease
• Depression sufficiently severe to compromise beneficiary’s ability to provide informed consent and limit likely clinical benefit of the treatment
• Severe cognitive impairment (such as may be defined by a score of
Summary of evidence (opening)
Essential Tremor (ET)
Essential tremor (ET) is the most common movement disorder as well as one of the most treated surgically. The prevalence of ET has been estimated at approximately 3% or 10 million people in the United States. While ET does not shorten life expectancy, the associated disabling symptoms, such as hand tremor, can greatly impact quality of life (functional ADLs, work activities, mood, and socialization).
Although there are no curative therapies, symptoms of ET are well managed medically in up to 70% of patients, with surgery reserved for medication-refractory severe impairments. Current surgical options include thalamotomy with radiofrequency (RF) ablation and deep-brain stimulation (DBS); both effectively suppress tremor but require intracranial surgery. Stereotactic radiosurgery (SRS), while non-operative, suffers from delay in tremor reduction (making intraoperative validation impossible), a greater than 10% cumulative risk of adverse events, and theoretical concerns about radiation side effects. 6, 22 DBS is currently the intervention of choice, “because of its proven efficacy, reversibility, adjustability, and durability” 22 , with thalamotomy “a reasonable alternative….if DBS is not available or practical”. 1 This attribute of DBS in creating an adjustable “functional lesion” causes fewer adverse events than thalamotomy 24, 25 , and resulted in a general shift away from ablation methods. 23
Neuromodulation with ultrasound energy also required craniotomy until recently; advances in ultrasound transducer design and high-resolution magnetic resonance imaging now allow precise transcranial delivery of high-intensity focused ultrasound. The ultrasound causes a local increase in temperature in the target tissue, resulting in coagulation necrosis while sparing the surrounding normal structures. In addition to providing location guidance, MRI provides real-time clinical monitoring of treatment intensity via thermal imagery. On 1/1/16, a CPT Category III tracking code specific to MRgFUS treatment of movement disorder became effective. FDA PMA approval for the Magnetic-Resonance-Guided Focused Ultrasound Surgery System (MRgFUS) (ExAblate Model 4000, InSightec, Inc.) “for the unilateral thalamotomy treatment of idiopathic essential tremor patients with medication-refractory tremor” came on 7/11/16. 3
The contractor cites 70 sources in the bibliography; the full summary and analysis of evidence are in the CMS record.
Dates, lineage and related policies
- Original determination effective
- 2019-04-01
- Current revision effective
- 2025-09-11
- MCD version
- 25
Other related documents: A59419 (Response to Comments), A59420 (Response to Comments).
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 Noridian Healthcare Solutions, LLC hub lists every other active policy from the same contractor.
The same policy title at other contractors
Contractors often adopt each other's policies and then revise them separately, so the criteria and the diagnosis lists drift apart. The topic comparison lines up every version.
Frequently asked questions
What does LCD L37729 cover?
This LCD addresses use of Magnetic-Resonance-Guided Focused Ultrasound Surgery (MRgFUS) for the treatment of idiopathic essential tremor (ET) patients including Tremor Dominant Parkinson's disease (TDPD) patients with medication-refractory tremor. 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 L37729 apply to?
Noridian Healthcare Solutions, LLC applies it to Medicare claims in AK, AS, AZ, CA, CNMI, GU, HI, ID, MT, ND, NF, NV, OR, SD, SF, UT, WA, WY. 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 L37729?
The companion billing and coding article A57512 lists 6 ICD-10-CM codes in 1 group that support medical necessity and 1 that do not; the first 6 appear on this page and the complete list is in the article on cms.gov.
How do I appeal a denial under LCD L37729?
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.
- Medicare Coverage Database, current LCD exportVersion MCD release 2026-09-24 · effective 2026-09-20 · file lcd.csvSHA-256 2fcc4251b6ddd1eb…
- Medicare Coverage Database, current Billing and Coding Articles exportVersion MCD release 2026-09-24 · effective 2026-09-20 · file article.csvSHA-256 f31932f1df3b4035…
- ICD-10-CM FY2027 code descriptionsVersion FY2027 · effective 2026-10-01 · file icd10cm_codes_2027.txtSHA-256 3c0583a38ee0e848…
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.