A4633 Replacement UV Therapy Bulb HCPCS Reimbursement | OpenPayer

Summary & Overview

HCPCS A4633: Replacement Bulb for Ultraviolet Light Therapy System

HCPCS Level II code A4633 denotes a replacement bulb or lamp for an ultraviolet light therapy system, a component used to deliver phototherapy treatments for dermatologic and other indications. Nationally, this code matters because it represents a recurring supply cost tied to outpatient phototherapy services and capital-maintenance of UV therapy equipment. Payers evaluate this supply both as a separately billable item and as part of episode-of-care costs for dermatology and phototherapy centers.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of the clinical and operational context for the code, typical sites of service, and which stakeholders commonly bill for replacement parts. The publication outlines typical billing elements associated with A4633, common modifiers used in practice, and the role of this supply in outpatient dermatology and phototherapy workflows.

The content summarizes benchmarks and payment considerations at a national level, highlights policy and coverage topics relevant to supply billing, and clarifies where to look for additional coding guidance. Data not available in the input is identified explicitly where applicable.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareA4633HCPCS Level IIultraviolet therapyphototherapydurable medical equipmentmedical suppliesdermatologyoutpatient billing

Billing Code Overview

HCPCS Level II code A4633 describes a replacement bulb/lamp for an ultraviolet light therapy system, each. The service type is durable medical equipment/supplies replacement part used to restore or maintain the function of an ultraviolet (UV) light therapy device. The typical site of service for this supply is outpatient clinics, dermatology practices, phototherapy centers, or other ambulatory settings where UV light therapy is administered.

Data not available in the input.

Clinical & Coding Specifications

Clinical Context

A dermatology clinic performs narrowband ultraviolet B (NB-UVB) phototherapy for patients with chronic skin conditions such as psoriasis, vitiligo, and atopic dermatitis. The clinic maintains phototherapy units that require periodic replacement of the ultraviolet lamp/bulb to ensure consistent spectral output and therapeutic dose delivery. A typical patient scenario: a 45-year-old with chronic plaque psoriasis attends thrice-weekly NB-UVB sessions; during preventive maintenance, a technician replaces the lamp using a replacement bulb billed as A4633 when the existing lamp reaches end of rated life or shows diminished output. The clinical workflow includes verification of the device and bulb model, documentation of the replacement (date, lot number, clinician/technician), confirmation of unit function and calibration post-replacement, and note in the patient’s record if treatment parameters change. Supplies are billed with the HCPCS Level II code A4633 as a single item for each replacement bulb/lamp used for the ultraviolet light therapy system.

Coding Specifications

Modifier	Description	When to Use
`00`	No modifier	Use when no specific modifier applies to the supply billing.

HCPCS A6575: Gradient Compression Arm Sleeve and Glove Combination

HCPCS-A4553-NON-DISPOSABLE-UNDERPAD-REUSABLE-UNDERPAD

HCPCS A4553: Non-Disposable Underpads, All Sizes

HCPCS-A4318-FEMALE-EXTERNAL-URINARY-COLLECTION-CUP-PER-DAY

HCPCS Level II A4318: Female External Urinary Collection Cup, Per Day

HCPCS-A6596-GRADIENT-COMPRESSION-CONFORMING-GAUZE-PER-LINEAR-YARD

HCPCS Level II A6596: Gradient Compression Conforming Gauze, Per Linear Yard

HCPCS-A6602-GRADIENT-COMPRESSION-FOAM-ROLL

HCPCS A6602: Gradient Compression Foam Roll, Per Linear Yard

HCPCS-A4216-STERILE-DILUENT-FLUSH-10ML

HCPCS A4216: Sterile Diluent/Flush, 10 ml

HCPCS-A6021-COLLAGEN-DRESSING-16-SQ-IN-OR-LESS

HCPCS A6021: Collagen Dressing, Sterile, ≤16 sq. in.

HCPCS-A6605-GRADIENT-COMPRESSION-FOAM-BANDAGING-SUPPLY-PER-YARD

HCPCS Level II A6605: Gradient Compression Padded Foam Bandaging, per Linear Yard

HCPCS-A6245-HYDROGEL-WOUND-DRESSING-16-SQ-IN-OR-LESS

HCPCS A6245: Hydrogel Wound Dressing, Sterile, ≤16 sq. in.

HCPCS-A4635-UNDERARM-PAD-CRUTCH-REPLACEMENT

HCPCS A4635: Underarm Pad, Crutch, Replacement, Each

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Taxonomy Code	Specialty	Notes
`207N00000X`	Dermatology	Dermatologists direct and supervise phototherapy programs.
`364A00000X`	Dermatology, Surgical	Providers performing procedural dermatology that may use phototherapy adjunctively.
`163W00000X`	Allied Health - Clinical Nurse Specialist	Clinical staff who may manage phototherapy units and perform clinical assessments.
`367500000X`	Medical Equipment Supplier	Suppliers or durable medical equipment providers who furnish replacement bulbs or maintain phototherapy devices.
`3336C0002X`	Dermatology Technician	Licensed technicians who operate and maintain phototherapy equipment and document bulb replacements.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`L40.0`	Psoriasis vulgaris	Common indication for NB-UVB or phototherapy; lamp replacement ensures effective therapy dosing.
`L80`	Vitiligo	Phototherapy is a standard treatment; replacement lamps maintain treatment efficacy.
`L20.9`	Atopic dermatitis, unspecified	Moderate to severe atopic dermatitis may be treated with phototherapy; lamp replacement is part of device maintenance.
`L30.0`	Nummular dermatitis	Phototherapy is used in refractory cases; functional lamps are required for consistent sessions.
`L21.9`	Seborrheic dermatitis, unspecified	Phototherapy sometimes used; lamp replacements support ongoing treatment.
`B35.3`	Tinea corporis	Phototherapy is less common but may be used adjunctively in select cases; lamp maintenance remains necessary.
`M32.9`	Systemic lupus erythematosus, unspecified	Photosensitive conditions may require specialized phototherapy planning; lamp performance must be documented.
`Z51.82`	Encounter for therapeutic drug monitoring	Represents follow-up encounters associated with therapy management where device supplies like replacement bulbs are documented.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`96910`	Photochemotherapy; topical application with ultraviolet light (e.g., PUVA)	Represents a phototherapy session that may use a replacement lamp billed separately with `A4633` when the UV source requires replacement.
`96912`	Photochemotherapy; initial treatment session (first 3 weeks), office or other outpatient facility	Related to initiation of a phototherapy course where equipment maintenance, including lamp replacement, is part of ensuring treatment quality.
`96913`	Photochemotherapy; subsequent treatment sessions	Ongoing therapy sessions that depend on functional lamps; replacement bulbs billed with `A4633` support reproducible treatments.
`99070`	Supplies and materials (except spectacles), provided by the physician over and above those usually included with the office visit	Used when supplies like replacement bulbs are billed separately and payer policy allows supply billing in addition to procedural codes.
`99000`	Handling and/or conveyance of specimen for transfer from the physician's office to another laboratory	Not directly related to lamp replacement but occasionally billed for ancillary services in the workflow when specimens are collected during visits.

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