Summary & Overview
HCPCS E1812: Dynamic Knee Extension/Flexion Device with Active Resistance Control
HCPCS Level II code E1812 identifies a dynamic knee extension/flexion device with active resistance control used in rehabilitative care. Nationally, this code represents a category of durable medical equipment (DME) that supports post-injury and post-operative knee therapy by enabling controlled, resistive range-of-motion and strengthening exercises. The code matters because it links a specific therapeutic device to coverage, billing, and documentation practices across major payers.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of how the device is categorized, typical sites of service where it is used (outpatient therapy clinics, rehabilitation centers, and home settings), and the clinical contexts that commonly drive utilization. The publication also summarizes benchmarking and policy considerations relevant to reimbursement for durable medical equipment, highlights documentation elements that support medical necessity, and outlines payer categories most likely to cover this device.
This summary is intended to give clinicians, billing staff, and policy analysts a concise national-level view of HCPCS Level II code E1812, the clinical role of the device it represents, and the payer landscape to consider when preparing claims and supporting documentation.
Billing Code Overview
HCPCS Level II code E1812 describes a dynamic knee, extension/flexion device with active resistance control. This device is designed to provide adjustable, user-controllable resistance during knee extension and flexion exercises to support rehabilitation and functional strengthening.
Service Type: Durable medical equipment — therapeutic exercise device
Typical Site of Service: Outpatient clinics, physical therapy departments, rehabilitation centers, and patient homes
Clinical & Coding Specifications
Clinical Context
A typical patient is a 45–70 year-old recovering from knee surgery (e.g., ACL reconstruction, total knee arthroplasty) or managing a knee extensor/flexor weakness after traumatic injury or neurologic insult. The device described by billing code E1812 — a dynamic knee extension/flexion device with active resistance control — is furnished when prescribed by an orthopedist, physiatrist, or physical therapist to provide controlled active-assisted range-of-motion and resistance training. The clinical workflow begins with an outpatient evaluation documenting range-of-motion deficits, quadriceps or hamstrings weakness, pain limiting active therapy, or postoperative stiffness. A prescription/order is written specifying device type, gait/weightbearing status, and fitting requirements. The device is dispensed in an orthopedic clinic, durable medical equipment (DME) provider office, or rehabilitation facility; a certified orthotist or trained DME technician performs fitting and patient education. Follow-up visits occur with the prescribing clinician and physical therapy team to adjust resistance settings, monitor skin integrity, and document functional gains. Billing uses E1812 as the HCPCS Level II supply line item; typical sites of service include outpatient orthopedic clinics, outpatient rehabilitation centers, ambulatory surgical centers for immediate postoperative provision, and patients’ homes when delivered by a DME supplier.
Coding Specifications
| Modifier | Description | When to Use |
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