Noninvasive Tests of Carotid Function — NCD 212 | CMS Coverage Update

TL;DR: The Centers for Medicare & Medicaid Services modified NCD 212, the National Coverage Determination governing Medicare coverage of noninvasive tests of carotid function, effective March 7, 2026. Here's what changes for billing teams.

CMS updated NCD 212 to reflect current coverage policy for diagnostic tests used to study and diagnose carotid artery disease. This policy covers a defined set of direct and indirect carotid function tests—including Doppler flow velocity, ultrasound imaging, oculoplethysmography, and periorbital directional Doppler ultrasonography. The policy does not list specific CPT or HCPCS codes, which creates a real documentation challenge your billing team needs to address before March 7, 2026.

Quick-Reference Table

CMS Noninvasive Carotid Function Tests Coverage Criteria and Medical Necessity Requirements 2026

NCD 212 covers noninvasive tests of carotid function when used to study and diagnose carotid artery disease. The coverage policy recognizes that these tests measure a range of anatomical and physiological parameters—pressure (systolic, diastolic, and pulse), flow, collateral circulation, and turbulence—and that no single test covers all of them.

CMS organizes covered tests into two categories. Direct tests examine the carotid artery itself. Indirect tests examine hemodynamic changes in the distal vascular beds—specifically the orbital and cerebral circulations.

The direct tests covered under NCD 212 include:

The indirect tests covered under NCD 212 include:

One thing that complicates reimbursement for these services: CMS explicitly acknowledges the test names are not standardized. The policy states that the listed tests are not inclusive and that local medical consultants—meaning your Medicare Administrative Contractor (MAC)—make coverage determinations for tests not named here. That's a meaningful gap. If your practice bills a test that falls into one of these categories but under a different name, your MAC has discretion, and you need documentation that connects your specific test to one of the covered categories.

Prior authorization is not mentioned in NCD 212. But the absence of a prior auth requirement doesn't mean you can skip the medical necessity documentation. For any claim denial risk on carotid testing under Medicare, your documentation needs to tie the test performed back to a covered indication—carotid disease evaluation—and to one of the recognized direct or indirect test types.

Coverage Indications at a Glance

CMS Noninvasive Carotid Function Tests Billing Guidelines and Action Items 2026

The absence of specific CPT or HCPCS codes in NCD 212 is the central billing challenge here. That's not an accident or an oversight—it's CMS deferring to MACs and letting the policy serve as a framework rather than a code list. For your billing team, that means the work is in the mapping, not just in the policy read.

Here's what to do before March 7, 2026:

If your practice has significant volume in vascular surgery, neurology, or radiology and you're unsure how NCD 212 maps to your current charge master, loop in your compliance officer before the March 7, 2026 effective date.

CPT, HCPCS, and ICD-10 Codes for Noninvasive Carotid Function Tests Under NCD 212

Covered CPT Codes (When Medical Necessity Criteria Are Met)

NCD 212 does not list specific CPT or HCPCS codes. This is not a gap in this article—it is the actual policy. CMS explicitly leaves code-level determinations to local MACs.

The correct step is to contact your MAC directly for a list of CPT and HCPCS codes payable under NCD 212 in your jurisdiction. Do not assume that codes you've been billing previously have been validated against the 2026 modification until you've confirmed that with your MAC.

Key ICD-10-CM Diagnosis Codes

NCD 212 does not specify ICD-10-CM codes. Your claims must support a carotid disease indication for medical necessity—work with your coding team and medical director to confirm appropriate diagnosis coding for carotid evaluation in your patient population.