HCPCS Level II L1821: Knee Orthosis, Elastic, Prefabricated, Off-the-Shelf

HCPCS Level II code L1821 describes a prefabricated, off-the-shelf elastic knee orthosis with condylar pads and joints, provided with or without patellar control; this is a durable medical equipment item intended for knee support/immobilization and is typically supplied in outpatient settings such as orthotics/prosthetics clinics, durable medical equipment providers, or outpatient rehabilitation facilities.

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HCPCS Level II L1821: Knee Orthosis, Elastic, Prefabricated, Off-the-Shelf

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Clinical & Coding Specifications

Clinical Context

A typical patient is an adult with medial or lateral knee instability, mild-to-moderate osteoarthritis, patellofemoral pain, or a ligament sprain who presents to an orthopedics or sports medicine clinic for nonoperative management. The clinician evaluates the patient via history and physical exam, documents range of motion, joint stability, swelling, and patellar tracking, and determines that an off-the-shelf elastic knee orthosis with condylar pads and joints is appropriate for support, compression, and patellar control. The orthotist or clinical staff measures the limb, fits a prefabricated device L1821, provides patient education on donning/doffing, wear schedule, skin care, and activity restrictions, and documents medical necessity, functional limitations, and expected therapeutic goals. Typical sites of service include outpatient orthopedics clinics, physical therapy clinics, physician offices, urgent care centers, and durable medical equipment supplier locations where fitting and patient instruction occur.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`97760`	Orthotic(s) management and supervision; initial encounter for fitting and training, each 15 minutes	Often billed by orthotists or therapists when fitting a prefabricated knee orthosis and providing patient education and training
`97763`	Orthotic/prosthetic management and evaluation, established patient, subsequent encounter	Used for follow-up adjustments, evaluation of fit, and continued training after initial fitting
`99213`	Office or other outpatient visit for the evaluation and management of an established patient, typically 15 minutes	Common physician visit code to evaluate the knee, document medical necessity, and write the DME order for `L1821`
`20550`	Injection, single tendon sheath, ligament, or ganglion cyst (if indicated)	May be performed in the same visit for knee injection therapy prior to bracing in certain workflows
`97001`	Physical therapy evaluation (historical CPT; use current equivalent)	Physical therapy evaluation often precedes or accompanies orthosis provision to document functional deficits and justify bracing

Related Modifiers

5 rows

Modifier	Description	When to Use
59	Modifier 59 indicates a distinct procedural service when two procedures that are not normally billed together are clinically and procedurally separate. The CPT definition (as reiterated by CMS)…	- Use modifier -59 to report a distinct procedural service when documentation supports that the procedure reported is not normally billed together with another service on the same day because of a…
52	Modifier ‑52 (Reduced Services) indicates that a service or procedure was partially reduced or omitted at the provider’s discretion, allowing reporting of the basic procedure number with a qualifier…	- Use modifier -52 when a physician or qualified health professional electively reduces or omits part of a procedure or service (for example, performing fewer required views or omitting a portion of…
63	Modifier‑63 is appended to surgical CPT codes (20000–69990) when a procedure is performed on a neonate or infant weighing ≤ 4 kg (about 8.8 lbs). The AMA/AAPC definition specifies this use and notes…	- Use modifier -63 only for surgical procedures in the CPT 20000–69990 series performed on a neonate or infant who weighs ≤ 4 kg at the time of the procedure; it indicates increased complexity due to…
55	Modifier –55 indicates the billing provider furnished only postoperative management for a procedure that has a global surgical period. According to AAPC, this modifier is appended to the same CPT…	- Use modifier -55 when billing the same CPT surgical code that has a 10- or 90-day global period and you, as a provider other than the original surgeon, furnished ONLY postoperative management (no…
P1	Modifier P1 indicates an ASA Physical Status I — a normal healthy patient — and is appended to anesthesia CPT codes (00100–01999) based on the anesthesiologist’s clinical assessment. It documents the…	- When to apply: Use modifier P1 on anesthesia CPT codes (00100–01999) when the anesthesia provider assigns ASA Physical Status I — a normal healthy patient (non‑smoker, minimal or no alcohol use).…

Related Provider Taxonomies

8 rows

Taxonomy Code	Specialty	Notes
208100000X	Physical Medicine & Rehabilitation Physician	Physical medicine and rehabilitation, also referred to as rehabilitation medicine, is the medical specialty concerned with diagnosing, evaluating, and…
2086S0122X	Plastic and Reconstructive Surgery Physician	A surgeon who specializes in plastic and reconstructive surgery.
207L00000X	Anesthesiology Physician	An anesthesiologist is trained to provide pain relief and maintenance, or restoration, of a stable condition during and immediately following an opera…
133VN1301X	Oncology Nutrition Registered Dietitian	An individual who is a Board Certified Specialist in Oncology Nutrition and provides direct nutrition care for individuals at risk for or diagnosed wi…
173000000X	Legal Medicine	The specialty areas of medicine concerned with matters of, and relations with, substantive law and legal institutions; such as the conduct of medical …
229N00000X	Anaplastologist	An anaplastologist is a professional who creates prostheses for the face and body. Patients treated include those missing anatomy due to cancer, trau…
101YM0800X	Mental Health Counselor	Behavioral Health & Social Service Providers · Counselor
261QH0700X	Hearing and Speech Clinic/Center	An entity, facility, or distinct part of a facility providing diagnostic, treatment, prescriptive, and therapy services related to congenital and acqu…

HCPCS L0112: Cranial Cervical Orthosis, Congenital Torticollis Type

HCPCS-L0113-CRANIAL-CERVICAL-ORTHOSIS-TORTICOLLIS

HCPCS Level II L0113: Prefabricated Cranial Cervical Orthosis for Torticollis

HCPCS-L0130-CERVICAL-FLEXIBLE-THERMOPLASTIC-COLLAR-MOLDED-TO-PATIENT

HCPCS Level II L0130: Cervical Flexible Thermoplastic Collar, Molded to Patient

HCPCS-L0140-CERVICAL-SEMI-RIGID-ADJUSTABLE-PLASTIC-COLLAR

HCPCS Level II L0140: Cervical Semi-Rigid Adjustable Plastic Collar

HCPCS-L0150-CERVICAL-SEMI-RIGID-ADJUSTABLE-CHIN-CUP

HCPCS Level II L0150: Cervical Semi-Rigid Adjustable Chin Cup

HCPCS-L0160-CERVICAL-SEMI-RIGID-OCCIPITAL-MANDIBULAR-SUPPORT

HCPCS Level II L0160: Cervical Semi-Rigid Occipital/Mandibular Support

HCPCS-L0170-CERVICAL-COLLAR-MOLDED-TO-PATIENT-MODEL

HCPCS Level II L0170: Cervical Collar, Custom-Molded

HCPCS-L0172-CERVICAL-COLLAR-SEMI-RIGID-THERMOPLASTIC-FOAM

HCPCS L0172: Cervical Collar, Semi-Rigid Prefabricated

HCPCS-L0174-CERVICAL-COLLAR-SEMI-RIGID-THORACIC-EXTENSION

HCPCS L0174: Cervical Collar, Semi-Rigid Thermoplastic with Thoracic Extension

HCPCS-L0180-CERVICAL-MULTIPLE-POST-COLLAR-OCCIPITAL-MANDIBULAR-ADJUSTABLE

HCPCS Level II L0180: Cervical Orthosis with Occipital/Mandibular Supports

Showing 1–10 of 466

Frequently Asked Questions

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

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Clinical & Coding Specifications

Clinical Context

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`97760`	Orthotic(s) management and supervision; initial encounter for fitting and training, each 15 minutes	Often billed by orthotists or therapists when fitting a prefabricated knee orthosis and providing patient education and training
`97763`	Orthotic/prosthetic management and evaluation, established patient, subsequent encounter	Used for follow-up adjustments, evaluation of fit, and continued training after initial fitting
`99213`	Office or other outpatient visit for the evaluation and management of an established patient, typically 15 minutes	Common physician visit code to evaluate the knee, document medical necessity, and write the DME order for `L1821`
`20550`	Injection, single tendon sheath, ligament, or ganglion cyst (if indicated)	May be performed in the same visit for knee injection therapy prior to bracing in certain workflows
`97001`	Physical therapy evaluation (historical CPT; use current equivalent)	Physical therapy evaluation often precedes or accompanies orthosis provision to document functional deficits and justify bracing

Related Modifiers

5 rows

Modifier	Description	When to Use
59	Modifier 59 indicates a distinct procedural service when two procedures that are not normally billed together are clinically and procedurally separate. The CPT definition (as reiterated by CMS)…	- Use modifier -59 to report a distinct procedural service when documentation supports that the procedure reported is not normally billed together with another service on the same day because of a…
52	Modifier ‑52 (Reduced Services) indicates that a service or procedure was partially reduced or omitted at the provider’s discretion, allowing reporting of the basic procedure number with a qualifier…	- Use modifier -52 when a physician or qualified health professional electively reduces or omits part of a procedure or service (for example, performing fewer required views or omitting a portion of…
63	Modifier‑63 is appended to surgical CPT codes (20000–69990) when a procedure is performed on a neonate or infant weighing ≤ 4 kg (about 8.8 lbs). The AMA/AAPC definition specifies this use and notes…	- Use modifier -63 only for surgical procedures in the CPT 20000–69990 series performed on a neonate or infant who weighs ≤ 4 kg at the time of the procedure; it indicates increased complexity due to…
55	Modifier –55 indicates the billing provider furnished only postoperative management for a procedure that has a global surgical period. According to AAPC, this modifier is appended to the same CPT…	- Use modifier -55 when billing the same CPT surgical code that has a 10- or 90-day global period and you, as a provider other than the original surgeon, furnished ONLY postoperative management (no…
P1	Modifier P1 indicates an ASA Physical Status I — a normal healthy patient — and is appended to anesthesia CPT codes (00100–01999) based on the anesthesiologist’s clinical assessment. It documents the…	- When to apply: Use modifier P1 on anesthesia CPT codes (00100–01999) when the anesthesia provider assigns ASA Physical Status I — a normal healthy patient (non‑smoker, minimal or no alcohol use).…

Related Provider Taxonomies

8 rows

Taxonomy Code	Specialty	Notes
208100000X	Physical Medicine & Rehabilitation Physician	Physical medicine and rehabilitation, also referred to as rehabilitation medicine, is the medical specialty concerned with diagnosing, evaluating, and…
2086S0122X	Plastic and Reconstructive Surgery Physician	A surgeon who specializes in plastic and reconstructive surgery.
207L00000X	Anesthesiology Physician	An anesthesiologist is trained to provide pain relief and maintenance, or restoration, of a stable condition during and immediately following an opera…
133VN1301X	Oncology Nutrition Registered Dietitian	An individual who is a Board Certified Specialist in Oncology Nutrition and provides direct nutrition care for individuals at risk for or diagnosed wi…
173000000X	Legal Medicine	The specialty areas of medicine concerned with matters of, and relations with, substantive law and legal institutions; such as the conduct of medical …
229N00000X	Anaplastologist	An anaplastologist is a professional who creates prostheses for the face and body. Patients treated include those missing anatomy due to cancer, trau…
101YM0800X	Mental Health Counselor	Behavioral Health & Social Service Providers · Counselor
261QH0700X	Hearing and Speech Clinic/Center	An entity, facility, or distinct part of a facility providing diagnostic, treatment, prescriptive, and therapy services related to congenital and acqu…

HCPCS L0112: Cranial Cervical Orthosis, Congenital Torticollis Type

HCPCS-L0113-CRANIAL-CERVICAL-ORTHOSIS-TORTICOLLIS

HCPCS Level II L0113: Prefabricated Cranial Cervical Orthosis for Torticollis

HCPCS-L0130-CERVICAL-FLEXIBLE-THERMOPLASTIC-COLLAR-MOLDED-TO-PATIENT

HCPCS Level II L0130: Cervical Flexible Thermoplastic Collar, Molded to Patient

HCPCS-L0140-CERVICAL-SEMI-RIGID-ADJUSTABLE-PLASTIC-COLLAR

HCPCS Level II L0140: Cervical Semi-Rigid Adjustable Plastic Collar

HCPCS-L0150-CERVICAL-SEMI-RIGID-ADJUSTABLE-CHIN-CUP

HCPCS Level II L0150: Cervical Semi-Rigid Adjustable Chin Cup

HCPCS-L0160-CERVICAL-SEMI-RIGID-OCCIPITAL-MANDIBULAR-SUPPORT

HCPCS Level II L0160: Cervical Semi-Rigid Occipital/Mandibular Support

HCPCS-L0170-CERVICAL-COLLAR-MOLDED-TO-PATIENT-MODEL

HCPCS Level II L0170: Cervical Collar, Custom-Molded

HCPCS-L0172-CERVICAL-COLLAR-SEMI-RIGID-THERMOPLASTIC-FOAM

HCPCS L0172: Cervical Collar, Semi-Rigid Prefabricated

HCPCS-L0174-CERVICAL-COLLAR-SEMI-RIGID-THORACIC-EXTENSION

HCPCS L0174: Cervical Collar, Semi-Rigid Thermoplastic with Thoracic Extension

HCPCS-L0180-CERVICAL-MULTIPLE-POST-COLLAR-OCCIPITAL-MANDIBULAR-ADJUSTABLE

HCPCS Level II L0180: Cervical Orthosis with Occipital/Mandibular Supports

Showing 1–10 of 466

Frequently Asked Questions

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

Published by

Trek Health powers OpenPayer with a leading commercial payer intelligence platform, seamlessly converting fragmented payer data into actionable insights for provider organizations.

OpenPayer

HCPCS Level II L1821: Knee Orthosis, Elastic, Prefabricated, Off-the-Shelf

Sign up for hcpcs L1821 policy alerts

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HCPCS Level II L1821: Knee Orthosis, Elastic, Prefabricated, Off-the-Shelf

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Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related Codes

References

Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related Codes

References

HCPCS Level II L1821: Knee Orthosis, Elastic, Prefabricated, Off-the-Shelf

Sign up for hcpcs L1821 policy alerts

HCPCS Level II L1821: Knee Orthosis, Elastic, Prefabricated, Off-the-Shelf

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Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related Codes

What device does HCPCS L1821 represent?

In what clinical contexts and sites of service is L1821 commonly used?

Which modifiers are commonly used with L1821 and when are they applied?

Which CPT codes are commonly billed with L1821 for fitting, training, or evaluation?

Which payers are discussed and what documentation do they typically review for L1821?

References

Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related Codes

What device does HCPCS L1821 represent?

In what clinical contexts and sites of service is L1821 commonly used?

Which modifiers are commonly used with L1821 and when are they applied?

Which CPT codes are commonly billed with L1821 for fitting, training, or evaluation?

Which payers are discussed and what documentation do they typically review for L1821?

References