Summary & Overview
HCPCS A6531: Below-Knee Gradient Compression Stocking, 30-40 mmHg
HCPCS Level II code A6531 identifies a single below-knee gradient compression stocking delivering 30–40 mmHg of pressure, designated for use as a surgical dressing. The code is used to bill for a disposable or single-item compression stocking applied in perioperative or post-operative settings to control edema, support venous return and protect surgical sites. Nationally, this code matters for uniform reporting of post-operative supply use, supply cost tracking, and clinical documentation supporting pressure-level selection.
Key payers addressed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare and Medicare. Readers will find an overview of the code’s clinical purpose and typical sites of service; summaries of payer coverage patterns where available; and context for billing and documentation expectations tied to its designation as a surgical dressing. The publication highlights benchmarks and policy considerations relevant to durable medical equipment and supply billing, plus common modifier usage and data gaps where specific payer policies or diagnosis mappings are not provided.
Data not available in the input is noted where payer-specific coverage rules, associated ICD-10 diagnoses, taxonomies, and related billing codes are not supplied.
Billing Code Overview
HCPCS Level II code A6531 describes a gradient compression stocking, below knee, 30-40 mmHg, used as a surgical dressing, each. This item is a single below-knee medical compression stocking intended to provide graduated compression in the 30–40 mmHg range and is specified for use as a surgical dressing.
Service Type: Medical supply — compression therapy / surgical dressing
Typical Site of Service: Hospital outpatient department, surgical center, post-operative care settings, or other ambulatory care sites where surgical dressings and compression therapy are applied.
Clinical & Coding Specifications
Clinical Context
A 62-year-old patient presents to the ambulatory surgical center immediately following varicose vein ligation and ambulatory dermatologic excision of a lower leg lesion. The surgeon applies a sterile, below-knee gradient compression stocking sized to deliver 30–40 mmHg to the operative limb as part of the post-procedure dressing and to reduce postoperative edema and venous stasis. Typical workflow: intraoperative dressing stage where the surgical team verifies limb laterality (LT/RT), sizes and places the stocking over sterile dressings, documents the item as a surgical dressing on the operative report and supply log, and charges the HCPCS Level II code A6531 on the claim with appropriate modifiers reflecting laterality or unusual circumstances. Typical site of service is an ambulatory surgery center or outpatient hospital surgical suite; the stocking is billed as a disposable, single-use item per limb.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
LT | Left side | Use when the stocking is applied to the left lower extremity |