CMS Updates Coverage Policy for Computer Enhanced Perimetry (NCD 261)

CMS has modified its National Coverage Determination for computer enhanced perimetry under NCD 261, effective March 12, 2026. This update affects how Medicare contractors evaluate and process claims for automated visual field testing—a procedure central to glaucoma management and neurological workups. If your practice bills for visual field assessments, here's exactly what you need to know before the effective date.

What Is Computer Enhanced Perimetry Under CMS Coverage Policy NCD 261?

Computer enhanced perimetry is a diagnostic technique that uses a microcomputer to measure visual sensitivity at preselected locations across the visual field. Unlike manual perimetry, the computer-assisted approach systematically maps the visual field with greater precision and repeatability—making it the standard of care for monitoring conditions like glaucoma, where subtle field changes over time carry significant clinical weight.

Under NCD 261, the Centers for Medicare & Medicaid Services classifies this service under the Diagnostic Tests (other) benefit category. This classification matters for billing purposes because it determines how claims are adjudicated and what documentation standards apply.

CMS Medical Necessity Criteria: When Computer Enhanced Perimetry Is Covered

CMS covers computer enhanced perimetry as a Medicare benefit when it is used to assess visual fields in patients with one of two qualifying conditions:

The policy language is intentionally broad on the neuropathologic side, which gives clinicians reasonable latitude—but "reasonable latitude" in CMS coverage doesn't mean documentation-free. The medical record needs to establish a clear clinical rationale connecting the patient's diagnosis to the need for perimetric assessment.

Coverage Distinction: What This Policy Does and Doesn't Say

The policy affirms coverage for the two qualifying indications above. It does not specify a frequency limitation within the NCD itself, which means frequency may be governed by local coverage determinations (LCDs) issued by your Medicare Administrative Contractor (MAC). Billing teams should confirm whether their MAC has an active LCD that supplements NCD 261 with additional frequency or documentation rules.

The policy does not designate computer enhanced perimetry as experimental or investigational for the covered indications. This is a covered service—the question is always whether the specific encounter meets the medical necessity threshold.

Affected Codes

The policy data for NCD 261 does not list specific CPT, HCPCS, or ICD-10 codes. Billing teams should reference their MAC's LCD, local billing articles, and the relevant CPT codebook sections for appropriate code selection when submitting claims under this NCD. Your compliance team should confirm current code assignments with your MAC before the March 12, 2026 effective date.

Prior Authorization Requirements for CMS Computer Enhanced Perimetry Claims

NCD 261 does not reference a prior authorization requirement for computer enhanced perimetry under Medicare. However, prior authorization requirements can vary by Medicare Advantage plan when commercial carriers administer Medicare benefits. If your practice sees Medicare Advantage patients, verify prior auth requirements directly with the specific plan—this NCD governs traditional Medicare only.

Documentation Best Practices for NCD 261 Medical Necessity

Even without a prior auth requirement, insufficient documentation is the primary reason claims for diagnostic tests get denied or recouped on audit. For computer enhanced perimetry claims under NCD 261, your clinical notes should address:

• The qualifying diagnosis — glaucoma or neuropathologic condition, documented with specificity
• Clinical rationale — why visual field testing is necessary at this encounter (new diagnosis, monitoring for progression, pre-operative assessment, change in symptoms, etc.)
• Ordering provider credentials — the ordering clinician must be authorized to order diagnostic tests under Medicare rules
• Results interpretation — a signed interpretation note from the supervising or interpreting physician should accompany the technical component claim where applicable

This is especially important for neuropathologic indications, where the connection between the systemic or neurological condition and the need for visual field testing may not be self-evident to a claims auditor.

What Your Billing Team Should Do