What Is the 92133 CPT Code?
CPT code 92133 bills OCT imaging of the optic nerve head and retinal nerve fiber layer with interpretation and report. It is the core structural test for detecting and monitoring glaucoma, measuring RNFL thickness, ganglion cell complex, and optic disc parameters. Under the 2026 Medicare Physician Fee Schedule, the national allowable is approximately $44 for the global code, paid once whether one or both eyes are scanned because the descriptor is unilateral or bilateral.
One code, both eyes. 92133 is billed once per encounter whether one or both eyes are scanned. Do not append modifier 50 or split into RT and LT lines.
Cannot pair with 92134. 92133 (optic nerve) and 92134 (retina) carry a mutually exclusive NCCI edit that no modifier can break. Only one may be billed per patient encounter.
Frequency-limited. Most Medicare LCDs cap 92133 at one to two scans per year for stable glaucoma. A third or fourth study denies without documented progression.
What Does the 92133 CPT Code Cover?
CPT 92133 covers OCT imaging of the optic nerve head and the surrounding retinal nerve fiber layer, plus the physician’s written interpretation and report. It measures RNFL thickness, ganglion cell complex, and optic disc parameters, which is why it is the primary structural test for detecting and monitoring glaucoma before visual field loss appears.
In 2025 the AMA revised the descriptor, replacing the old term scanning computerized ophthalmic diagnostic imaging (SCODI) with computerized ophthalmic diagnostic imaging and adding OCT as the example, so 92133 and its old SCODI label describe the same test. The optic nerve version, 92133, is distinct from the retina version, 92134, and the scan protocol run on the device must match the code billed. An optic nerve head protocol supports 92133, while a macular protocol supports 92134.
What Is the Difference Between 92133 and 92134?
92133 images the optic nerve and 92134 images the retina, and they sit in the same OCT family with distinct clinical uses. 92133 is the glaucoma and optic nerve code, while 92134 is the workhorse for macular disease such as age-related macular degeneration and diabetic macular edema. Only one may be billed per encounter. For the retinal side of the OCT family, see our guide to OCT of the retina (92134).
| CPT code | What it images | Primary use |
|---|---|---|
| 92132 | Anterior segment OCT | Cornea, angle, and anterior chamber |
| 92133 | Posterior segment, optic nerve | Glaucoma and optic nerve disease |
| 92134 | Posterior segment, retina | Macular degeneration, diabetic macular edema |
| 92137 | Posterior segment with angiography (OCT-A) | Retinal and choroidal vessels, added in 2025 |
Can You Bill 92133 and 92134 on the Same Day?
No. Per AMA CPT and NCCI edits, you cannot report 92133, 92134, or 92137 at the same patient encounter, and this edit carries a modifier indicator that no modifier can break, even when the two tests target different diagnoses in different eyes. When both regions are imaged, bill the single code tied to the primary diagnosis or the more clinically significant finding. This is different from the fundus photography edit. 92133 is also bundled with fundus photography (92250), but that pair can be separated with modifier 59 when each test is documented as separately necessary.
Which Diagnoses Support 92133?
92133 is payable only when a glaucoma or optic nerve diagnosis on the same date establishes medical necessity, and the diagnosis must appear in the payer’s local coverage policy. Pairing 92133 with a retinal code such as macular degeneration denies, because the optic nerve scan is not the test indicated for that condition.
- Primary open-angle glaucoma in the H40.11 family, which requires a seventh-character stage (mild, moderate, severe, or indeterminate).
- Glaucoma suspect and preglaucoma in the H40.00 family.
- Ocular hypertension in the H40.05 family.
- Optic neuritis and related inflammation in the H46 family.
- Ischemic optic neuropathy in the H47.01 family.
- Papilledema and optic atrophy in the H47.1 and H47.2 families.
Glaucoma imaging is high-volume and frequency-edited, so a clean 92133 workflow protects more revenue than another scan does. Compare vetted ophthalmology billing companies that handle OCT frequency rules, TC and PC splits, and diagnosis pairing, and get matched in about 30 minutes at no cost.
What Modifiers Does 92133 Use?
Because 92133 is bilateral by descriptor, the laterality and bilateral modifiers that apply to most codes do not apply here.
| Modifier | When to append | Common pitfall |
|---|---|---|
| TC | Technical component when the practice owns the OCT device | Billing global when another entity read the scan |
| 26 | Professional interpretation and report only | Missing the written report that 26 requires |
| 59 | To separate 92133 from a bundled 92250 when each is justified | Trying to use it to pair 92133 with 92134, which no modifier allows |
| 50 | Not used on 92133 | Appending it anyway, which triggers a bilateral reduction or denial |
Why Do 92133 Claims Get Denied?
Most 92133 denials come from four causes: a diagnosis that does not support optic nerve imaging, frequency that exceeds the local coverage limit, two units billed for a bilateral code, and a scan protocol that does not match the code. Medicare covers 92133 only for a documented glaucoma or optic nerve indication, not as a screening of a healthy eye.
Frequency is the quiet one. Many MAC local coverage determinations cap 92133 at roughly one to two scans per year for stable glaucoma, so a third or fourth study in the same benefit period denies without explicit documentation of progression, an intraocular pressure spike, or a treatment change. A note that simply says abnormal does not satisfy the interpretation-and-report requirement, and billing 92133 when the device log shows a macular protocol invites recoupment, since the scan type must match the code.
What Does Unmanaged 92133 Denial Volume Actually Cost?
The money is not in the $44 you collect on a clean 92133; it is in the volume of glaucoma imaging a practice repeats every year. If a practice monitors 400 stable glaucoma patients and images each of them quarterly out of habit, the third and fourth studies fall outside the typical one-to-two-per-year coverage limit, roughly 800 denied scans and about $35,000 in unpaid imaging before appeals. The leak compounds when the diagnosis does not match, since pairing 92133 with a retinal code auto-denies. In one published ophthalmology case study, a single quarter of unworked denials totaled $151,695 across modifier errors, invalid diagnostic-imaging code pairings, and OCT denials. For practices also tracking visual field testing, our CPT 92083 visual field billing guide covers the parallel frequency and documentation rules that apply to the other half of the glaucoma monitoring workflow.
Frequently Asked Questions
Once per encounter whether one or both eyes are scanned. The descriptor reads unilateral or bilateral and the code carries a bilateral indicator of 2. Do not append modifier 50, do not report RT and LT on separate lines, and do not use 52 for a single eye. The medically unlikely edit allows only one unit.
Sometimes. 92133 and fundus photography (92250) are bundled under NCCI, but the edit carries a modifier indicator that allows modifier 59 when each test is separately medically necessary and documented. Without that documentation, expect payment on only the higher-valued code.
Frequency is set by each Medicare Administrative Contractor, but most local coverage policies allow roughly one to two optic nerve OCT studies per year for stable glaucoma. More frequent monitoring requires documented clinical justification such as RNFL progression, a recent pressure spike, or a change in treatment.
A qualifying glaucoma or optic nerve diagnosis, an optic nerve head scan protocol that matches the code, and a distinct written interpretation and report with the physician’s findings and treatment implications. A brief note such as ‘abnormal’ is not enough, and a missing interpretation is one of the most common audit failures for OCT.
Covered indications include glaucoma in the ICD-10 H40 family (such as primary open-angle glaucoma H40.1131 with its seventh-character stage), glaucoma suspect and ocular hypertension in the H40.00 and H40.05 families, and optic nerve disorders in the H46 and H47 families. Retinal codes such as macular degeneration do not support 92133.
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