👁️ CPT 76513 — Ophthalmic Ultrasound, Diagnostic; Anterior Segment Ultrasound, Immersion (Water Bath) B-Scan or High Resolution Biomicroscopy, Unilateral or Bilateral
Quick Reference
wRVU: 0.60 | Global Period: 000 | Assistant Payable: No | Bilateral Indicator: 3 Rule: CPT 76513 carries a technical “000” global designation for billing-system purposes, but as a diagnostic radiology test it functionally has no global surgical period at all (payment concept is XXX in CMS terms).¹ Its bilateral indicator of “3” means the fee already contemplates unilateral or bilateral performance under one code — Medicare bases payment on the technical component regardless of side count rather than applying the standard 150% bilateral surgery multiplier.² This is a diagnostic-only code; it carries no assistant-at-surgery allowance since no surgical act occurs.
📋 Clinical Description
CPT 76513 describes an ultrasound-based imaging study of the anterior segment of the eye — the cornea, anterior chamber, iris, ciliary body, and posterior lens surface — performed using either immersion (water bath) B-scan technique or ultrasound high-resolution biomicroscopy (UBM).³ Unlike a slit-lamp exam or gonioscopy, this modality penetrates opaque or narrow structures using sound waves, allowing visualization of anatomy hidden behind an edematous cornea, a miotic pupil, or a shallow anterior chamber that limits direct optical viewing. This code sits alongside 76510 (B-scan and quantitative A-scan) and 76512 (B-scan alone) in the ophthalmic ultrasound family, but is distinguished by its specific focus on the anterior rather than posterior segment.
Clinically, 76513 is most frequently ordered to investigate mechanisms of angle-closure glaucoma — plateau iris configuration, aqueous misdirection (malignant glaucoma), ciliary body cysts or tumors pushing the iris forward, and post-traumatic angle recession. Because Medicare and most commercial payers restrict routine use of this code for standard open-angle glaucoma monitoring, documentation must support a specific anatomical question that only UBM or immersion ultrasound can answer, distinguishing it from the far more commonly billed 76514 (corneal pachymetry) which measures thickness alone rather than structural anatomy.⁴
This procedure may be performed in the following clinical contexts:
- Suspected plateau iris syndrome — evaluating anterior placement of the ciliary body causing angle crowding despite a normal-appearing iris plane on slit lamp.
- Post-traumatic angle recession — following blunt ocular trauma, to characterize angle structures obscured by hyphema or corneal edema.
- Aqueous misdirection (malignant glaucoma) — assessing ciliary body-lens-vitreous relationships in a patient with a shallow chamber despite a patent iridotomy.
- Ciliary body or iris mass evaluation — imaging a suspected cyst, melanoma, or other lesion of the ciliary body not visualized by standard exam.
- Pre-surgical planning for angle-closure intervention — characterizing angle anatomy before iridotomy, goniosynechialysis, or lens extraction in narrow-angle patients.
🔬 Anatomical & Procedural Considerations
| Variant | Mechanism | Key Notes |
|---|---|---|
| Immersion B-scan (water bath) | A fluid-filled scleral shell or eyecup is placed over the globe to create an acoustic coupling medium, and a B-scan transducer is passed over the closed eyelid or through the immersion medium to generate cross-sectional images of anterior structures without corneal contact. | Avoids corneal compression artifact seen with contact-probe techniques, which is critical when precise anterior chamber depth measurements are needed for glaucoma mechanism classification. |
| High-resolution ultrasound biomicroscopy (UBM) | A high-frequency transducer (35-50 MHz) provides near-histologic resolution of the iris, ciliary body, and angle recess, at the cost of shallower tissue penetration than standard B-scan. | UBM is the preferred technique for ciliary body pathology and angle-closure mechanism differentiation because of its superior resolution of the ciliary sulcus and pars plicata. |
| Combined/comparative approach | Some practices perform both immersion B-scan and UBM in the same encounter when a mass extends beyond UBM’s shallow penetration depth but requires UBM’s superior resolution at the anterior margin. | Only one unit of 76513 is reportable regardless of whether one or both techniques are used in the same session, since the code descriptor bundles both modalities under a single service. |
Clinical Pearl
Payers increasingly restrict 76513 to a defined list of secondary or atypical glaucoma diagnoses rather than allowing it for routine open-angle glaucoma follow-up.⁵ Confirm the ordering diagnosis matches an accepted LCD indication (anatomical narrow angle, aqueous misdirection, angle recession, or angle-closure glaucoma) before coding, since a mismatched diagnosis is one of the most common denial reasons for this code.
✅ Procedure Includes
- Positioning and application of the immersion scleral shell or coupling medium for the water-bath technique.
- Acquisition of B-scan or UBM images of the cornea, anterior chamber angle, iris, and ciliary body.
- Real-time dynamic assessment of angle structures, including any provocative maneuvers performed during the same encounter.
- Measurement and documentation of anterior chamber depth, angle width, and any identified mass or structural abnormality.
- Physician interpretation and written report correlating ultrasound findings with the clinical indication.
- Image storage and permanent retention as part of the medical record supporting medical necessity.
❌ Excludes / Do Not Report Together
| Code | Description | Relationship |
|---|---|---|
| 76510 | Ophthalmic ultrasound, diagnostic; B-scan and quantitative A-scan performed during the same patient encounter | Targets the posterior segment rather than the anterior segment; reportable together only if separate, medically necessary indications exist for both posterior and anterior imaging in the same encounter. |
| 76512 | Ophthalmic ultrasound, diagnostic; B-scan (with or without superimposed non-quantitative A-scan) | Also a posterior-segment code; bundling edits generally prevent reporting both 76512 and 76513 for the same session unless distinct medical necessity for each segment is clearly documented. |
| 76514 | Ophthalmic ultrasound, diagnostic; corneal pachymetry, unilateral or bilateral | Measures corneal thickness only rather than anterior chamber or ciliary body anatomy; may be reported same-day with 76513 if both a structural anterior segment question and a thickness measurement are separately indicated. |
| 92132 | Scanning computerized ophthalmic diagnostic imaging, anterior segment, with interpretation and report | Represents the OCT-based (optical, not ultrasound) alternative for anterior segment imaging; the two are mutually exclusive for the same clinical question since they use different technologies to answer overlapping questions. |
Bundling Alert
Because 76513 has no global surgical period, there is no post-op restriction, but NCCI edits still apply when multiple ophthalmic ultrasound or imaging codes are billed the same day.⁶ Auditors frequently flag claims where 76513 is billed for a routine glaucoma-monitoring diagnosis rather than one of the accepted secondary/angle-closure indications, and payers may request the ultrasound images and interpretation to substantiate medical necessity before reimbursing.
🌳 Code Tree — Diagnostic Ultrasound Procedures (Head and Neck)
CPT 76506-76999 Radiology: Diagnostic Ultrasound
│
├── 76506-76516 Ophthalmic Ultrasound, Diagnostic
│ ├── 76510 Ophthalmic ultrasound, diagnostic; B-scan and quantitative A-scan performed during the same patient encounter (Global: 000)
│ ├── 76512 Ophthalmic ultrasound, diagnostic; B-scan (with or without superimposed non-quantitative A-scan) (Global: 000)
│ ├── ▶▶ 76513 ◀◀ Ophthalmic ultrasound, diagnostic; anterior segment ultrasound, immersion (water bath) B-scan or high resolution biomicroscopy, unilateral or bilateral ← YOU ARE HERE (Global: 000)
│ ├── 76514 Ophthalmic ultrasound, diagnostic; corneal pachymetry, unilateral or bilateral (determination of corneal thickness) (Global: 000)
│ └── 76516 Ophthalmic biometry by ultrasound echography, A-scan (Global: 000)
│
├── 76519 Ophthalmic biometry by ultrasound echography, A-scan; with intraocular lens power calculation
│
└── 76529-76536 Other Head and Neck Ultrasound
├── 76529 Ophthalmic ultrasonic foreign body localization
└── 76536 Ultrasound, soft tissues of head and neckNo National LCD Exists…
CPT 76513 is almost always bundled into the identical B-scan policy documents as 76512 and 76510, since all three describe variations of ophthalmic ultrasound imaging. This means whichever LCD/Article your MAC uses for 76512 will also list 76513 in its code group — you won’t find a separate standalone LCD just for 76513 in most jurisdictions
| MAC / Jurisdiction | Document covering 76513 | Notes |
|---|---|---|
| First Coast Service Options (FCSO), Jurisdiction N | LCD L33904 “B-Scan” | Same bundled group as 76510/76512, still the reference doc for 76513 aao |
| Palmetto GBA, Jurisdictions J/M (your jurisdiction) | SCODI-family LCD/Article, code lookup via palmettogba.com | Palmetto keeps an active LCD/Article index searchable by CPT code rather than a single static ID palmettogba |
| Noridian | DME MAC LCD/Policy Article revisions (updated Jan 2026) | Not typically applicable unless billed under DME; relevant mainly for immersion probe supply codes, not the professional service itself med.noridianmedicare |
| CGS, Jurisdiction B | LCD list searchable via Ctrl+F code lookup tool | CGS explicitly instructs finding LCDs by HCPCS/CPT code search rather than by title cgsmedicare |
| WPS GHA | April 2026 LCD and Billing/Coding Article update page | Confirms MACs continue splitting LCDs from companion Billing & Coding Articles into 2026 wpsgha |
Key clinical distinction for 76513
Where 76512 evaluates the posterior segment (retina, vitreous, choroid) when the view is obstructed, 76513 specifically covers anterior segment structures — cornea, anterior chamber, iris, ciliary body — typically performed via immersion (water bath) technique or ultrasound biomicroscopy. This distinction matters for your ICD-10-CM pairing work, since anterior segment conditions (glaucoma evaluation, iris/ciliary body tumors, corneal opacities affecting angle structures) justify 76513, while posterior pathology justifies 76512 — payers will deny if the diagnosis doesn’t match the anatomic region actually imaged.
💰 RVU & Reimbursement Profile
| Component | Value |
|---|---|
| Work RVU | 0.60 |
| Global Period | 000 (XXX concept — no true global surgical period) |
| Bilateral Indicator | 3 |
| Assistant Surgeon | Not applicable (diagnostic test) |
| Co‑Surgeon | Not applicable |
| Team Surgery | Not applicable |
| PC/TC Split | 1 (splittable via modifiers 26/TC) |
| Modifier -51 Exempt | No |
| Anesthesia | Not applicable |
Bilateral Billing Rules
Despite the descriptor stating “unilateral or bilateral,” several regional coding references note payers still expect modifier -50, -RT, or -LT appended, or two units reported, when both eyes are scanned in the same encounter.⁷ Confirm your specific MAC or payer’s bilateral billing instruction before submission, since practice varies by contractor for this particular code.
🏷️ Modifier Reference
| Modifier | Name | When to Apply |
|---|---|---|
| -RT | Right Side | Append when the study is performed on the right eye only, per payer-specific bilateral billing convention for this code. |
| -LT | Left Side | Append when the study is performed on the left eye only, per payer-specific bilateral billing convention for this code. |
| -50 | Bilateral | Append (or report 2 units) per several payer instructions when both eyes are imaged in the same session, despite the descriptor’s inclusive wording. |
| -25 | Significant E/M | Applies to a same-day E/M service, not to 76513 itself; append to the E/M code when a significant, separately identifiable evaluation is performed alongside the ultrasound. |
| -51 | Multiple Procedures | Applies when 76513 is billed with other separately payable procedures in the same session, subject to standard multiple-procedure reduction rules. |
| -59 | Distinct Service | Use to indicate 76513 is a distinct diagnostic service from another same-day ultrasound code when NCCI edits would otherwise bundle them, if documentation supports separate medical necessity. |
| -26 | Professional Component | Use when only the physician interpretation is being billed and the technical acquisition was performed by a separate entity, such as in a hospital-owned facility. |
| -TC | Technical Component | Use when only the equipment/technical acquisition is being billed, such as when the facility owns the ultrasound equipment and a separate physician bills professional component only. |
| -77 | Repeat Procedure by Another Physician | Applies when a different physician repeats the same ultrasound study later the same day for a new clinical reason. |
🩺 Common ICD‑10‑CM Pairings
Primary Diagnosis Group
| ICD‑10 | Description | HCC? | Notes |
|---|---|---|---|
| H40.033 | Anatomical narrow angle, bilateral | No | This is one of the AAO-endorsed accepted indications for 76513, since UBM directly visualizes angle crowding mechanisms not seen on gonioscopy alone.⁸ |
| H40.2313 | Acute angle-closure glaucoma, bilateral | No | Supports urgent imaging need to determine whether pupillary block, plateau iris, or lens-related mechanisms are driving the acute presentation. |
| H40.833 | Aqueous misdirection, bilateral | No | A classic accepted indication; UBM demonstrates the anteriorly rotated ciliary processes characteristic of malignant glaucoma. |
| H40.323 | Glaucoma secondary to eye trauma, bilateral, chronic stage | No | Supports imaging of angle recession or cyclodialysis cleft following blunt trauma. |
| H21.539 | Degeneration of iris and ciliary body, unspecified eye | No | Applies when a ciliary body cyst or degenerative change is the primary imaging target rather than a glaucoma mechanism. |
Secondary Group
| ICD‑10 | Description | HCC? | Notes |
|---|---|---|---|
| H21.31 | Cyst of iris | No | Supports medical necessity when a visible or suspected iris cyst requires depth/extent characterization. |
| Q15.0 | Congenital glaucoma | No | Applies in rare inpatient pediatric or young-adult consults evaluating congenital angle anomalies. |
Etiology / Complication
| ICD‑10 | Description | HCC? | Notes |
|---|---|---|---|
| S05.00XA | Injury of conjunctiva and corneal abrasion without foreign body, right eye, initial encounter | No | Relevant when post-traumatic anterior segment ultrasound is performed acutely to rule out occult angle or ciliary body injury. |
| T85.398A | Mechanical complication of other ocular prosthetic devices and implants, initial encounter | No | Applies when imaging investigates a suspected implant-related anterior segment complication, such as a malpositioned intraocular lens affecting angle anatomy. |
Coding Specificity Reminder
Always code to the full 7-character ICD-10-CM specificity available, including laterality and, where applicable, encounter type. Avoid unspecified glaucoma stage or laterality codes when the clinical note documents a specific eye and disease stage, since payer LCDs for this test are often diagnosis-list-driven and unspecified codes are a leading cause of denial.
Clinical Distinction: 76513 vs. 76512
| Feature | 76513 (Anterior Segment/UBM) | 76512 (Diagnostic B-Scan) |
|---|---|---|
| Primary Target | Anterior chamber, iris, ciliary body. | Retina, choroid, vitreous, optic nerve. |
| Typical Use Case | Angle-closure glaucoma, iris tumors. | retinal detachment, vitreous hemorrhage. |
| Resolution | Very high (microscopic detail). | Moderate (gross anatomical detail). |
🏥 MS‑DRG Considerations
CPT 76513 is a non-surgical diagnostic ancillary service and does not independently drive MS-DRG assignment in the inpatient facility setting; its ICD-10-PCS imaging equivalent is reported facility-side alongside the primary surgical or medical DRG-determining procedure. When performed during an inpatient stay as a professional-fee consult (e.g., ophthalmology consult for a hospitalized patient with acute angle-closure glaucoma), the professional fee is captured under 76513 while the facility separately reports the corresponding Section B Imaging PCS code; neither typically reclassifies the DRG unless the underlying diagnosis itself is a CC/MCC.
🔧 ICD‑10‑PCS Equivalents
| PCS Code | Full Description | Modality |
|---|---|---|
| B840ZZZ | Ultrasonography, Bilateral Eyes | Ultrasonography |
| B8407ZZ | Ultrasonography, Left Eye, Rebreathing Mode | Ultrasonography |
| B8417ZZ | Ultrasonography, Right Eye, Rebreathing Mode | Ultrasonography |
| B8402ZZ | Ultrasonography, Bilateral Eyes, Densitometry Study | Ultrasonography |
PCS Character Analysis
| Position | Character | Value | Definition |
|---|---|---|---|
| 1 | Section | B | Imaging section, distinct from the Medical/Surgical (0) section since no tissue is altered. |
| 2 | Body System | 8 | Represents the Eye body system within the Imaging section’s classification. |
| 3 | Root Operation | 4 | Ultrasonography root type — using sound wave energy for real-time visualization rather than ionizing radiation or contrast dye. |
| 4 | Body Part | 0/1/2 | Bilateral, Left, or Right Eye, selected according to which globe(s) were scanned during the encounter. |
| 5 | Approach/Contrast | Z | No contrast used, since ultrasonography does not require an injected contrast agent. |
| 6 | Device | Z | No qualifying device value applies to this imaging study. |
| 7 | Qualifier | Z | No additional qualifier value applies unless a specialized densitometry study is separately coded. |
Root Operation Comparison
- Ultrasonography (root type 4) is distinguished from Plain Radiography (0) and Fluoroscopy (1) by its use of sound waves rather than ionizing radiation, which is clinically relevant given the eye’s radiosensitivity.
- Unlike Computerized Tomography (2) or Magnetic Resonance Imaging (3), Ultrasonography provides real-time dynamic imaging, which is essential for observing angle structures during provocative positioning maneuvers.
📝 Coding Examples
Example 1
Clinical Scenario: A 68-year-old woman with a history of narrow angles on gonioscopy presents to the ophthalmology clinic for evaluation prior to cataract surgery. The surgeon is concerned about plateau iris configuration given a persistently shallow angle despite a patent laser iridotomy. High-resolution ultrasound biomicroscopy is performed on the right eye only to characterize the ciliary body position relative to the iris root. The study confirms anteriorly positioned ciliary processes consistent with plateau iris syndrome.
| Field | Code | Rationale |
|---|---|---|
| CPT | 76513--RT | Unilateral study of the right eye only; RT reported per payer-specific unilateral billing convention. |
| PDx | H40.033 | Anatomical narrow angle is the accepted glaucoma-mechanism indication supporting UBM medical necessity. |
Note
Documentation must specifically identify the ciliary body findings and angle mechanism to support medical necessity separate from a routine narrow-angle gonioscopy exam already on file.
Example 2
Clinical Scenario: A 45-year-old man is seen emergently after blunt trauma to the left eye from an airbag deployment. Slit-lamp exam shows a shallow anterior chamber with layered hyphema obscuring the angle view. Immersion B-scan ultrasound is performed to evaluate for angle recession and to rule out a ciliary body cyclodialysis cleft, since direct gonioscopy is not possible through the hyphema. Corneal pachymetry is also performed the same day to establish a baseline thickness given anticipated steroid use.
| Field | Code 1 | Rationale |
|---|---|---|
| CPT 1 | 76513--LT | Immersion B-scan of the traumatized left eye to assess angle recession obscured by hyphema. |
| CPT 2 | 76514 | Corneal pachymetry performed same day for a distinct clinical purpose (baseline thickness), separately reportable from 76513. |
| PDx | S05.00XA | Documents the traumatic mechanism prompting the imaging on this initial encounter. |
Warning
Example 3
Clinical Scenario: A 72-year-old inpatient on the medicine service develops acute vision changes and eye pain during a hospital stay for an unrelated cardiac admission. Ophthalmology is consulted and finds markedly shallow anterior chambers bilaterally with elevated intraocular pressures. Ultrasound biomicroscopy of both eyes is performed at bedside to evaluate for aqueous misdirection syndrome versus pupillary block, given the patient’s recent initiation of a sulfa-based diuretic known to precipitate this reaction. Findings confirm bilateral anterior rotation of the ciliary body consistent with aqueous misdirection.
| Field | Code | Rationale |
|---|---|---|
| CPT | 76513--50 | Bilateral study performed at bedside during an inpatient consult; modifier -50 reported per payer-specific bilateral convention. |
| PDx | H40.833 | Aqueous misdirection is a well-recognized accepted indication supporting this imaging study. |
Global period reminder
Since 76513 carries no true global surgical period, there is no post-procedure follow-up restriction; however, if a subsequent surgical intervention (e.g., pars plana vitrectomy for aqueous misdirection) is later performed, that procedure’s own global period applies independently of this diagnostic test.
⚠️ Common Coding Pitfalls
- Pitfall 1: Billing 76513 for routine primary open-angle glaucoma monitoring rather than a specific angle-closure or secondary glaucoma mechanism, which is one of the most frequent reasons payers deny this code. Confirm the ordering diagnosis matches an accepted anatomical indication before submission.
- Pitfall 2: Confusing 76513 with 76514 (corneal pachymetry) since both are anterior-segment ophthalmic ultrasound codes; these measure entirely different things — anatomy versus thickness — and are not interchangeable.
- Pitfall 3: Failing to append -RT, -LT, or -50 per the specific payer’s bilateral billing instruction, since national guidance on this point is inconsistent despite the code’s inclusive “unilateral or bilateral” descriptor.
- Pitfall 4: Reporting 92132 (OCT-based anterior segment imaging) and 76513 together for the same clinical question, when payers generally consider these mutually exclusive technologies answering the same diagnostic need.
- Pitfall 5: Omitting a detailed interpretive report describing the specific angle or ciliary body findings, since a generic “unremarkable” note without correlation to the ordering diagnosis increases audit and denial risk.
- Pitfall 6: Assuming assistant-at-surgery or global period rules apply, when in fact this is a diagnostic test with no surgical global concept and no assistant surgeon allowance.
📎 Sources
¹ CMS National Physician Fee Schedule Relative Value File, 2026² CMS Medicare Physician Fee Schedule bilateral surgery indicator definitions
³ AAPC Codify, CPT Code 76513 Summary, 2026
⁴ AAPC Coding Alert, "Navigate the Nuances of Ophthalmic Ultrasound Coding," 2023
⁵ EmblemHealth Claims Corner, "Ophthalmic Ultrasound CPT Code 76513" (AAO-based coverage criteria), 2026
⁶ CMS National Correct Coding Initiative Policy Manual, Radiology chapter
⁷ AAPC Coding Alert, ophthalmic ultrasound bilateral billing guidance, 2023
⁸ EmblemHealth Claims Corner, accepted glaucoma-type indications for CPT 76513, 2026
Sources reflect publicly available payer and coding-reference guidance current as of July 2026; verify exact wRVU and bilateral indicator values against your current CMS PFS release and local MAC policy before claim submission, as national fee schedule files were not directly queryable at time of writing.