Summary & Overview
HCPCS Q4021: Short Arm Plaster Splint, Adult (11+)
HCPCS Level II code Q4021 designates an adult short arm plaster splint (for patients 11 years and older). This supply-level code captures the provision of plaster materials used to form a short arm splint for immobilization of the forearm, wrist or distal radius/ulna. Nationally, supply codes such as Q4021 matter for appropriate billing of non-procedural immobilization materials and for aligning coverage and payment across outpatient and emergency care settings. Key payers in scope include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare and Medicare.
Readers will learn what Q4021 represents clinically and operationally, the typical sites of service where the supply is used, and the context for billing supply items versus bundled casting procedures. The publication summarizes common modifiers and coding considerations (when available), notes payer coverage patterns and billing practices, and provides benchmarks and policy context where applicable. Data not available in the input will be identified as such in relevant sections. This summary is intended for national audiences including coding professionals, revenue cycle staff, and clinicians involved in immobilization care.
Billing Code Overview
HCPCS Level II code Q4021 represents cast supplies, short arm splint, adult (11 years +), plaster. This supply is used to create a short arm plaster splint intended for immobilization of the forearm, wrist or distal radius/ulna in patients aged 11 years and older.
Service Type: Durable medical supply / casting material
Typical Site of Service: Outpatient clinic, emergency department, ambulatory surgery center, or other outpatient settings where splinting and casting supplies are provided
Clinical & Coding Specifications
Clinical Context
A 45-year-old adult presents to an urgent care clinic after a fall onto an outstretched hand while playing recreational sports. The patient reports acute wrist pain, swelling, and limited range of motion. Point-of-care radiographs performed in clinic demonstrate a non-displaced distal radius fracture. The treating clinician elects to immobilize the wrist with a short arm plaster splint for initial management and pain control prior to orthopedic follow-up.
The clinical workflow: triage and brief history/physical, focused musculoskeletal exam, wound check (if applicable), obtain and review wrist radiographs, discuss treatment options and obtain informed consent for splinting, apply Q4021 cast supplies (short arm splint, adult, plaster) with appropriate padding and plaster splint material, provide patient education on splint care and signs of complications, schedule follow-up with orthopedics within 7–10 days for re-evaluation and possible conversion to a definitive cast or operative planning. Supplies are documented in the procedure note and billed using the Q4021 HCPCS Level II code along with the relevant evaluation and management or procedural codes as appropriate.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
LT | Left side |