Summary & Overview

HCPCS G2104: Retinal Imaging Validated to Seven-Field Stereoscopic Photos

HCPCS Level II code G2104 identifies diagnostic retinal imaging that is validated against seven-standard-field stereoscopic photographic results with documentation and review. Nationally, this code captures a specialized ophthalmic imaging service used primarily in retinal disease assessment and management; it supports clinical decision-making where stereoscopic photographic comparison is required. Payers commonly covering this service in national analyses include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.

Readers will learn what the code represents clinically, typical sites of service, and which major payers are included in coverage comparisons. The publication outlines the clinical context for use — specialized retinal imaging validated to match established stereoscopic photo protocols — and summarizes available benchmarks, common modifier usage, and policy considerations affecting billing and documentation. Where granular data elements were not provided in the input, the report notes that those specific fields are not available. The content is intended to inform billing staff, compliance teams, and clinical leaders about the role of G2104 in coding retinal imaging services and where to expect this code to appear in outpatient ophthalmology and specialty imaging settings.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareG2104HCPCS Level IIretinal imagingophthalmologydiagnostic imagingstereoscopic photosdocumentationoutpatient imagingmedical billing

Billing Code Overview

HCPCS Level II code G2104 describes eye imaging validated to match diagnosis from seven standard field stereoscopic photos results documented and reviewed. This service involves imaging of the retina and posterior segment that is specifically validated against a seven-standard-field stereoscopic photographic protocol, with results documented and interpreted.

Service type: Diagnostic retinal imaging and comparison/validation against seven-standard-field stereoscopic photographs
Typical site of service: Ophthalmology clinics, retinal specialty centers, and outpatient imaging facilities

Data not available in the input.

Clinical & Coding Specifications

Clinical Context

A 68-year-old patient with known proliferative diabetic retinopathy is referred for documentation of fundus imaging to validate a previously recorded diagnosis from seven standard field stereoscopic fundus photography. The patient presents to an outpatient ophthalmology clinic or an ambulatory imaging center. After a dilated fundus examination by the ophthalmologist, the clinic technician acquires widefield or montage retinal images using a validated imaging device. The ophthalmologist reviews the imaging, compares the digital images to the findings previously documented from the seven standard field stereoscopic photos, and documents that the eye imaging is validated to match the prior diagnosis. The service is typically performed in an outpatient clinic, ambulatory surgical center pre- or post-operative assessment, or hospital outpatient department when comparison and documentation of imaging-confirmed diagnosis are required for clinical management, treatment planning, or payer documentation. Common reasons include confirmation of diabetic retinopathy staging, monitoring of age-related macular degeneration, or verification of retinal detachment documentation prior to surgical scheduling.

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	Use when work required to validate and document imaging is substantially greater than typical (e.g., complex correlation with prior seven-field stereo photos).
`23`	Unusual anesthesia	Not commonly used for this imaging procedure but available when general anesthesia is required for the imaging in an otherwise unanesthetized procedure.
`52`	Reduced services	Use when imaging was partially completed or limited compared with standard validated imaging.
`53`	Discontinued procedure	Use if imaging began but was stopped due to patient intolerance or acute event.
`54`	Surgical care only	Use when another provider performs the imaging validation as part of broader surgical care and the performing provider is billing only the surgical portion.
`55`	Postoperative management only	Use if the billing provider is only providing postoperative imaging validation separate from intraoperative care.
`56`	Preoperative management only	Use when the provider bills only the preoperative imaging validation visit.
`62`	Two surgeons	Use when two surgeons of different specialties are required to validate complex imaging findings and both bill for their distinct services.
`AS`	Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery	Rare for imaging validation but used when an advanced practice clinician assists in the validation process under applicable payer rules.
`CO`	Clinic or outpatient hospital	Use to indicate the setting when required by specific payer reporting rules.
`CQ`	Services performed by a physical therapist assistant	Not typically applicable; not used for ophthalmic imaging but listed among available modifiers.
`FX`	Complex surgical tray	Not generally applicable to imaging but available when complex instrumentation billing rules apply in the perioperative setting.
`QK`	Medical direction of two, three, or four concurrent anesthesia procedures	Not typically applicable to diagnostic imaging validation but included if anesthesia direction is billed concurrently.
`QX`	CRNA service with medical direction by a physician	See `QK` context; rarely relevant unless anesthesia is involved.

Taxonomy Code	Specialty	Notes
`207UX0100X`	Ophthalmology	Ophthalmologists interpret and validate retinal imaging and document correlation with seven-field stereoscopic photos.
`208000000X`	Optometry	Optometrists may perform imaging acquisition and preliminary review in ambulatory settings where scope of practice allows.
`363L00000X`	Diagnostic Imaging	Imaging technicians and diagnostic imaging specialists perform image acquisition and technical aspects of validation.
`2084P0800X`	Retina Specialist (Ophthalmology sub-specialty)	Retina specialists frequently validate complex retinal imaging and correlate with stereoscopic photography for treatment decisions.
`163WL0500X`	Physician Assistant	Physician assistants commonly assist in imaging workflows and documentation under supervising physician protocols.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`H35.011`	Nonexudative age-related macular degeneration, right eye	Imaging validation documents macular findings and correlates with stereoscopic photos for staging and monitoring.
`H35.012`	Nonexudative age-related macular degeneration, left eye	As above for the left eye.
`H35.021`	Exudative age-related macular degeneration, right eye	Exudative changes require imaging confirmation to guide treatment; validated imaging supports diagnosis.
`H35.22`	Diabetic retinopathy, proliferative	Seven-field stereoscopic photos are a historical standard for staging; current imaging validation documents progression or stability.
`H33.00`	Retinal detachment, unspecified eye	Imaging validation can corroborate stereo photo findings prior to surgical planning.
`H35.371`	Choroidal neovascularization, right eye	Imaging helps confirm neovascular membranes noted on stereoscopic photography and guides therapeutic decisions.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`92250`	Fundus photography with interpretation and report	Often performed alongside validation imaging; provides photographic documentation of the retina used to correlate with seven-field stereoscopic photos.
`92134`	Scanning computerized ophthalmic diagnostic imaging, posterior segment, with interpretation and report, unilateral or bilateral	OCT imaging commonly complements stereoscopic photo validation by documenting macular and retinal architecture.
`92133`	Scanning computerized ophthalmic diagnostic imaging, posterior segment, with interpretation and report, unilateral or bilateral; retina and optic nerve, with quantitative analysis	Used when quantitative analysis of retinal layers or nerve fiber layer is required in addition to photographic validation.
`92227`	Remote imaging for detection of retinal disease (e.g., telehealth retinal imaging screening) with report, unilateral or bilateral, with remote interpretation	May be used when images are acquired remotely and an interpreting provider validates the imaging against prior seven-field stereoscopic photos.
`67028`	Intravitreal injection of a pharmacologic agent	May occur after validation of imaging confirms indication for intravitreal therapy (e.g., diabetic macular edema).