Lower Limb Orthoses

Affected Providers

Treating practitioners and DME suppliers who bill for lower limb orthoses.

HCPCS & CPT Codes

Local Coverage Determination (LCD): Ankle-Foot/Knee-Ankle-Foot Orthosis (L33686) and LCD: Knee Orthoses (L33318) have the current HCPCS and CPT codes.

Background

According to the 2024 Medicare Fee-for-Service Supplemental Improper Payment Data, the improper payment rate for lower limb orthoses is 35.2%, with a projected improper payment amount of $91.2 million.

We outline other requirements in Article: Standard Documentation Requirements for All Claims Submitted to DME MACs (A55426).

Denial Reasons

Insufficient documentation accounted for 39.5% of improper payments for lower limb orthoses during the 2024 reporting period, while no documentation (29.6%), medical necessity (8.6%), and other errors (22.2%) also caused improper payments. “Other” errors include duplicate payment, non-covered or unallowable service, or ineligible Medicare patient errors.

Preventing Denials

Coverage Criteria

The most common cause of improper payments was insufficient documentation, which means something to support payment for the items billed was missing from submitted medical records. According to our guidelines, claims with insufficient documentation are those lacking 1 or more of these:

• Valid order that includes all elements required by regulation, Medicare Program manuals, and Medicare Administrative Contractor (MAC)-specific guidelines
• Proof of delivery (missing or inadequate) per regulations and Medicare Program manuals
• Clinical documentation to support medical necessity of DME item (missing or inadequate)

The Medicare braces benefit covers ankle-foot orthoses (AFO) and knee-ankle foot Orthoses (KAFO). For coverage under this benefit, the orthosis must be a rigid or semi-rigid device, used for supporting a weak or deformed body member or restricting or eliminating motion in a diseased or injured body part. Items that aren’t rigid enough to be capable of providing necessary immobilization or support to a body part it’s designed for don’t meet the statutory definition of the braces benefit, so we don’t cover them.

We cover AFOs not used during ambulation, as described by HCPCS codes L4396 or L4397, if the patient either all of criteria 1–4 or criterion 5:

1. Plantar flexion contracture of the ankle (find the ICD-10-CM Codes that Support Medical Necessity section for Group 1 in Article: Ankle-Foot/Knee-Ankle-Foot Orthoses (A52457)) with dorsiflexion on passive range of motion testing of at least 10 degrees (a nonfixed contracture)
2. Reasonable expectation of the ability to correct contracture
3. Contracture interferes or you expect it to interfere significantly with the patient’s functional abilities
4. Used as a part of a therapy program, which includes actively stretching the involved muscles or tendons
5. The patient has plantar fasciitis (find the ICD-10 Codes that Support Medical Necessity section for Group 1 in Article A52457)

We cover AFOs used during ambulation (as described by HCPCS codes L1900, L1902, L1904, L1906, L1907, L1910, L1920, L1930, L1932, L1933, L1940, L1945, L1950, L1951, L1952, L1960, L1970, L1971, L1980, L1990, L2106, L2108, L2112, L2114, L2116, L4350, L4360, L4361, L4386, L4387, and L4631) for ambulatory patients with weakness or deformity of the foot and ankle who both:

• Require stabilization for medical reasons
• Have the potential to benefit functionally

We cover KAFOs, as described by codes L2000, L2005, L2010 – L2038, L2126 – L2136, and L4370, for ambulatory patients for whom an AFO is covered and who require additional knee stability.

We deny orthoses as not reasonable and necessary if the patient doesn’t meet these basic coverage criteria for an AFO or a KAFO.

Billing & Coding Criteria

42 CFR 414.402 states that minimal self-adjustment is when a patient, patient’s caretaker, or supplier can perform an adjustment and doesn’t need the services of a certified orthotist or a person who has specialized training. Correctly coding AFO and KAFO items depends on whether the items needed minimal self-adjustment during the final fitting at the time of delivery. Code items requiring minimal self-adjustment as OTS orthoses. For example, adjustment of straps and closures, bending, or trimming for final fit or comfort (not all-inclusive) fall into this category.

Off-the-shelf orthotics require minimal self-adjustment for use and don’t require expertise in trimming, bending, molding, assembling, or customizing to fit a patient.

For custom-fit codes, include documentation that’s sufficiently detailed to include, but isn’t limited to, a detailed description of the modifications necessary at the time of fitting the patient’s orthosis.

Documentation Requirements

To justify payment, you must meet specific requirements when ordering DMEPOS.

Example of Improper Payments Due to Insufficient Documentation for Lower Limb Orthoses

A supplier bills the claim for L1851 (Knee orthosis (KO), single upright, thigh and calf, with adjustable flexion and extension joint (unicentric or polycentric), medial-lateral and rotation control, with or without varus/valgus adjustment, prefabricated, off-the-shelf) and submits the following documentation per the review contractor’s request:

• Standard written order with correct HCPCS coding
• Treating practitioner’s medical record that has adequate medical necessity information
• Proof of delivery with face-to-face encounter 7 months ago

What Documentation Was Missing?

The doctor didn’t document the face-to-face encounter within 6 months of proof of delivery.

What Happens Next?

The review contractor completes the claim as an insufficient documentation error, and the MAC recoups payment.

Recommendation

To avoid billing errors and improper payments, the certifying physician must collect and submit proper documentation, including a face-to-face encounter, in the treating practitioner’s medical record for DMEPOS.