Clinical Context
A 68-year-old ambulatory patient with symptomatic medial compartment knee osteoarthritis presents to an orthopedic clinic complaining of activity-related knee pain and intermittent instability. Conservative measures including NSAIDs, physical therapy, and activity modification provided limited relief. The orthopedist assesses alignment, range of motion, and ligamentous stability, determines the patient is not an immediate surgical candidate, and prescribes a prefabricated single‑upright knee orthosis with an adjustable flexion/extension joint for medial‑lateral and rotational control (K0901). The durable medical equipment (DME) supplier verifies measurements, performs a fitting in the clinic or outpatient DME clinic, educates the patient on donning/doffing, joint adjustment, skin inspection, and a progressive wear schedule. Follow‑up occurs within 2–6 weeks to reassess fit, comfort, and symptom response, and again as clinically indicated for adjustments or replacement. Typical sites of service include outpatient orthopedic clinics, hospital outpatient departments, ambulatory surgery centers for fittings adjacent to procedures, and durable medical equipment supplier clinics.
Coding Specifications
| Modifier | Description | When to Use |
|---|
59 | Distinct procedural service | Use when reporting a separately identifiable DME-related procedure or service performed the same day as another reportable service when clinical documentation supports distinctness. |
GA | Waiver of liability statement on file | Use when a voluntary Medicare advance beneficiary notice (ABN) is on file for this orthosis if not expected to be covered.
GQ | Via asynchronous telecommunication system | Use when a remote/telehealth orthotic measurement or fitting component was performed and billed under permitted telecommunication rules.
GK | Replacement of DME under warranty | Use when the orthosis is replaced under the original supplier warranty without additional patient cost.
NU | New equipment | Use when the orthosis is initial issue (new, not repair or replacement).
RR | Rental equipment | Use when billing for a rented knee orthosis under rental coverage rules instead of purchase codes.
LT | Left side | Use to indicate the orthosis is for the left knee when laterality is required by payer rules.
RT | Right side | Use to indicate the orthosis is for the right knee when laterality is required by payer rules.
Q6 | Certified by orthotist | Use when the orthosis fitting and certification were performed by a certified orthotist.
KX | Requirements specified in the medical policy have been met | Use when documentation supports that payer-specific medical necessity criteria for the orthosis are met.
| Taxonomy Code | Specialty | Notes |
|---|
207K00000X | Orthopedic Surgery | Surgeons evaluating and prescribing knee orthoses for joint disease or post‑op protection. |
232Y00000X | Physical Medicine & Rehabilitation | Physiatrists managing conservative care and orthotic interventions.
225100000X | Physical Therapist | PTs perform functional assessment and participate in fitting and training for orthosis use.
332B00000X | Prosthetist/Orthotist | Specialists who measure, fit, adjust, and certify DME orthoses.
363L00000X | Nurse Practitioner | Advanced practice providers who may prescribe and manage orthotic care.
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|
M17.11 | Unilateral primary osteoarthritis, right knee | Primary indication for an unloading/support orthosis to reduce pain and improve function. |
M17.12 | Unilateral primary osteoarthritis, left knee | As above, for the left knee.
M23.2 | Derangement of meniscus due to old tear or injury | Orthosis may provide stability and symptom relief when conservative care is indicated.
S83.241A | Bucket-handle tear of medial meniscus, right knee, initial encounter | Short- to mid-term bracing for instability or post‑injury protection in conservative management.
M25.561 | Pain in right knee | Symptom code commonly paired with orthotic prescription for pain management and functional assistance.
M25.562 | Pain in left knee | As above for left knee.
M22.2 | Recurrent dislocation of patella | A knee orthosis with rotation and medial-lateral control can assist with patellar stabilization in nonoperative care.
M23.9 | Internal derangement of knee, unspecified | Broad diagnosis under which an orthosis may be prescribed for mechanical symptoms or instability.
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|
99213 | Office or other outpatient visit for the evaluation and management of an established patient, typically 15 minutes | Used for the outpatient follow-up visit to evaluate orthosis effectiveness, fit, and need for adjustment. |
97001 | Physical therapy evaluation | Used when a physical therapist performs an initial functional and gait assessment to determine orthosis needs.
97530 | Therapeutic activities, direct (one-on-one) | May be used for supervised gait training and functional activities during orthosis fitting and rehabilitation.
99070 | Supplies and materials provided by physician over and above those usually included with the office visit | Use for minor orthotic accessories supplied by the clinic at fitting when payer allows billing.
A9270 | Non-covered item or service (miscellaneous DME supply) — HCPCS Level II example shown as CPT-adjacent supply code | Used by some payers for miscellaneous orthotic supplies not separately coded when required by supplier billing workflows.