Summary & Overview
HCPCS Q4359: Choriply, Per Square Centimeter (Add-On)
HCPCS Level II code Q4359 designates Choriply billed per square centimeter as an add-on product supplied in addition to a primary procedure. This code captures use of a biologic or tissue-derived graft component applied during a surgical or procedural episode and is relevant for hospitals, ambulatory surgery centers, and clinicians who bill for adjunctive graft materials. Nationally, add-on supply codes like Q4359 influence episode-level costing and facility supply tracking, and they affect bundled payment calculations and device/supply reporting.
Key payers covered include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the code’s clinical context, typical sites of service, and billing characteristics. The publication also outlines benchmarks and policy considerations relevant to add-on biologic supply codes, common modifier usage patterns, and payer coverage dynamics where available. Data not available in the input will be noted where applicable. The content is intended to inform billing staff, revenue cycle managers, and policy analysts about the role and reporting of Q4359 in surgical supply billing and reimbursement workflows.
Billing Code Overview
HCPCS Level II code Q4359 represents Choriply billed per square centimeter as an add-on procedure that must be listed separately in addition to a primary procedure. The service type is a biologic/derivative graft application delivered in conjunction with another surgical or procedural intervention. The typical site of service is an operating room or procedural suite where the primary procedure is performed.
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A patient with a full-thickness skin defect following wide local excision of a malignant or complex cutaneous lesion arrives for operative reconstruction. The surgical team prepares to apply a biologic dermal matrix product, billed as Q4359 (Choriply) on a per-square-centimeter, add-on basis to support wound bed regeneration and integration beneath a split-thickness skin graft or flap. Typical workflow: preoperative assessment documents diagnosis and wound dimensions; intraoperative measurement of the defect in square centimeters guides the quantity of Q4359 to be applied; the product is secured to the wound bed, overlaid with appropriate dressings, and grafting or secondary closure is performed either during the same encounter or in a staged manner. Postoperative notes document area treated (cm2), any device lot numbers, and whether the application was adjunctive to primary reconstructive procedures.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | No modifier | Use when no modifier applies to the service billed with Q4359. |