Optic Nerve Imaging (OCT of Optic Nerve)
CPT 92133 is an optical coherence tomography (OCT) scan of the optic nerve, primarily used to monitor glaucoma. It measures the thickness of the nerve fiber layer around the optic disc, detecting thinning that indicates glaucoma damage. Used over 2.3 million times per year in Medicare, providers charge an average of $103.07 but Medicare pays only $30.73 (a 3.4x markup, one of the highest in ophthalmology). The scan takes about 5 minutes on a machine that also performs retinal OCT (92134), and many practices routinely order both scans at every visit, doubling your imaging charges even when only one is clinically needed.
CPT 92133 at a Glance
- Average provider charge: $103.07
- Medicare rate (office): $30.73
- Medicare rate (hospital): $30.73 (same, equipment-driven)
- Typical markup: 3.4x over Medicare rate
- Test type: OCT scan of optic nerve
- Primary use: Glaucoma monitoring
- Scan duration: About 5 minutes
- Beneficiaries (2023): 2.3 million
On this page
How the Medicare Rate Is Calculated
Medicare prices every procedure using Relative Value Units (RVUs) across three components, then multiplies by a national conversion factor of $33.4009 (2026). Here is the exact math for a 92133 optic nerve OCT scan. Like visual field testing, the PE RVU is the same in both settings because the OCT machine costs the same regardless of location:
| Component | What It Covers | Office (Non-Facility) | Hospital (Facility) |
|---|---|---|---|
| Work RVU | Physician interpretation time | 0.25 | 0.25 |
| Practice Expense RVU | OCT machine, technician time | 0.65 | 0.65 |
| Malpractice RVU | Professional liability insurance | 0.02 | 0.02 |
| Total RVU | 0.92 | 0.92 | |
| x $33.4009 | 2026 conversion factor | $30.73 | $30.73 |
Medicare Rate by State
Medicare adjusts the national rate based on your location using Geographic Practice Cost Indices (GPCIs). The same 92133 scan pays differently in each state, but the range is narrow (about $24 to $28) because the low Work RVU minimizes geographic variation.
Medicare Rate by State (2026)
Medicare adjusts payments by location using Geographic Practice Cost Indices (GPCIs). Select your state to see the adjusted rate.
Sample State Rates
| State | Medicare Pays | Avg. Charge | Markup |
|---|---|---|---|
| Texas (Austin) | $26.06 | $103.07 | 4.0x |
| California (Los Angeles) | $26.72 | $103.07 | 3.9x |
| New York (Manhattan) | $27.00 | $103.07 | 3.8x |
| Florida (Fort Lauderdale) | $25.86 | $103.07 | 4.0x |
| Ohio | $24.95 | $103.07 | 4.1x |
| Mississippi | $24.23 | $103.07 | 4.3x |
| Arkansas | $24.14 | $103.07 | 4.3x |
| Alaska | $28.46 | $103.07 | 3.6x |
Rates shown use 2026 GPCIs and the $33.4009 conversion factor. The average provider charge of $103.07 is the 2023 national average from CMS utilization data. Actual charges vary by provider.
What Insured Patients Actually Pay for a 92133 Scan
If you have health insurance, you do not pay the provider's full charge of $103.07. Your insurer has a negotiated rate, typically 120% to 200% of the Medicare rate. For a 92133 scan, that negotiated rate is usually $35 to $60. What you owe depends on your plan design:
| Your Situation | What You Likely Pay | How It Works |
|---|---|---|
| Copay plan (deductible met) | $0 to $40 | May be bundled under the office visit copay or have a separate diagnostic test copay |
| Coinsurance plan (deductible met) | $7 to $12 | 20% of the negotiated rate ($35 to $60) |
| High-deductible plan (deductible NOT met) | $35 to $60 | You pay the full negotiated rate until your deductible is met |
| Medicare Part B | $6.15 | 20% of the Medicare-approved amount ($30.73) |
| Medicaid | $0 to $3 | Minimal or no cost-sharing in most states |
Should You Use Insurance or Pay Cash?
For an OCT scan alone, the cash-pay question is straightforward: the test is quick and the cash price is typically $30 to $75 at most practices. But since it is rarely done in isolation (you are usually getting an exam and other tests too), the real question is whether to put the entire visit through insurance or pay cash for everything.
When Cash-Pay Wins
- Your deductible is very high and nowhere near being met
- The provider offers an "all-in" cash price for the entire glaucoma visit
- You only need the OCT scan (not a full exam) and the provider will accommodate
When Using Insurance Wins
- Your deductible is already met and you only owe coinsurance ($6 to $12)
- You are getting multiple tests at the same visit (total adds toward deductible)
- You are close to meeting your out-of-pocket maximum
- You need documentation for insurance continuity of glaucoma care
Common Billing Problems with 92133
Routinely ordering both 92133 and 92134 when only one is needed
This is the most common overcharge with OCT scans. CPT 92133 scans the optic nerve (for glaucoma) and CPT 92134 scans the retina (for macular degeneration, diabetic retinopathy). Both tests use the same OCT machine but target different structures. Many practices order both at every visit as a "complete" scan, but if you are being monitored only for glaucoma, the optic nerve scan (92133) alone is typically sufficient. Ask your doctor: "Do I need both the optic nerve and retinal scan today, and if so, why?"
Excessive testing frequency
For stable glaucoma patients, annual OCT imaging is generally sufficient. Some practices run OCT scans at every visit (every 3 to 6 months) even when the optic nerve has been stable for years. While Medicare does not have a hard annual limit, coverage requires medical necessity. If your OCT results have been unchanged across multiple visits, ask whether you can extend the interval to once per year. This can save you $60 to $100 per skipped test.
The 3.4x markup on uninsured patients
At $103.07 versus the $30.73 Medicare rate, the 92133 markup is 3.4x. This means uninsured patients or those on high-deductible plans are paying three to four times what Medicare considers the fair value. If you are paying out of pocket, ask the provider for a cash-pay rate or Medicare-based rate. Many practices will discount to $40 to $60 if asked, which is still above the Medicare rate but far below the sticker price.
OCT ordered without a clear diagnosis
OCT scans of the optic nerve are primarily indicated for glaucoma or suspected glaucoma. If you do not have glaucoma, glaucoma suspect status, or another optic nerve condition, the test may not be medically necessary. Some practices include OCT as part of a "comprehensive technology package" for all patients. If you see 92133 on your bill and you have not been told you have (or are suspected of having) a glaucoma-related condition, ask the office to explain the clinical indication.
Related Eye Care Codes
| Code | Description | Medicare Rate | Avg. Charge |
|---|---|---|---|
| 92014 | Comprehensive eye exam, established patient | $127.26 | $219.94 |
| 92083 | Extended visual field exam | $63.80 | $147.34 |
| 92133 | OCT scan, optic nerve | $30.73 | $103.07 |
| 92134 | OCT scan, retina | ~$37 | ~$115 |
| 92250 | Fundus photography | ~$45 | ~$100 |
Frequently Asked Questions
How much does an OCT scan of the optic nerve (92133) cost without insurance?
Without insurance, an OCT optic nerve scan billed under CPT 92133 costs $60 to $175 depending on the provider and location. The national average charge is $103.07. Many ophthalmologists offer a cash-pay rate of $40 to $80. For comparison, Medicare pays only $30.73, making this one of the most marked-up codes in ophthalmology at 3.4x.
What is the difference between 92133 and 92134?
CPT 92133 is an OCT scan of the optic nerve, used primarily for glaucoma monitoring. CPT 92134 is an OCT scan of the retina, used for conditions like macular degeneration and diabetic retinopathy. Both are performed on the same OCT machine but scan different structures of the eye. They are billed as separate codes, and when ordered together at the same visit, they double the imaging charges.
Do I need both an optic nerve OCT (92133) and a retinal OCT (92134) at the same visit?
Not necessarily. If you are being monitored only for glaucoma, 92133 (optic nerve) is typically sufficient. If you are being monitored only for macular degeneration or diabetic retinopathy, 92134 (retina) is typically sufficient. Both scans are justified when you have conditions affecting both the optic nerve and the retina. Ask your doctor which scan is clinically needed for your specific condition.
How often does Medicare cover OCT scans for glaucoma?
Medicare does not have a strict per-year frequency limit for OCT scans, but coverage requires medical necessity. For stable glaucoma, most payers consider annual OCT scanning appropriate. More frequent scanning (every 6 months) may be justified if the condition is progressing or treatment has recently changed. Routine OCT at every visit without documented clinical need may be denied by Medicare.
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