Clinical UM Guideline

This document addresses orthoses for the ankle-foot or the knee-ankle-foot. The purpose of an orthosis (rigid or semi-rigid brace) is to support a weak or deformed body part, or to restrict or eliminate motion in a diseased or injured part of the body.

Note: Please see the following related documents for additional information:

• CG-DME-19 Therapeutic Shoes, Inserts, or Modifications for Individuals with Diabetes
• CG-DME-20 Orthopedic Footwear
• CG-OR-PR-02 Prefabricated and Prophylactic Knee Braces
• CG-OR-PR-03 Custom-made Knee Braces
• CG-OR-PR-09 Microprocessor Controlled Knee-Ankle-Foot Orthosis
• SURG.00104 Extraosseous Subtalar Joint Implantation and Subtalar Arthroereisis

Note: For a high-level overview of this document, please see "Summary for Members and Families" below.

Medically Necessary:

An ankle-foot orthosis (AFO) is considered medically necessary for ambulatory ( that is, able to walk, independently or with assistance) individuals with weakness or deformity of the foot and ankle who require stabilization for medical reasons and have the potential to benefit functionally.

Knee-ankle-foot orthoses (KAFOs) are considered medically necessary for ambulatory individuals for whom an ankle-foot orthosis is appropriate and additional knee stability is required.

AFOs and KAFOs that are custom-fabricated are considered medically necessary for ambulatory individuals when medically necessary criteria are otherwise met and one or more of the following criteria are met:

1. The individual could not be fit with a prefabricated AFO; or
2. The condition necessitating the orthosis is expected to be permanent or of longstanding duration (more than 6 months); or
3. There is a need to control the knee, ankle, or foot in more than one plane; or
4. The individual has a documented neurological, circulatory, or orthopedic status that requires custom fabricating to prevent tissue injury; or
5. The individual has a healing fracture which lacks normal anatomical integrity or anthropometric proportions.

Walking boots used to provide immobilization as treatment for an orthopedic condition or after orthopedic surgery are considered medically necessary.

A static AFO is considered medically necessary for non-ambulatory individuals if all of the following criteria are met:

1. Plantar flexion contracture of the ankle with dorsiflexion on passive range of motion testing of at least 10 degrees (that is, a non-fixed contracture); and
2. Reasonable expectation of the ability to correct or prevent a fixed contracture in those who may become ambulatory; and
3. Contracture is interfering or expected to interfere significantly with the individual’s functional abilities; and
4. Used as a component of a therapy program that includes passive stretching of the involved muscles or tendons.

Note: If a static AFO is used for the treatment of a plantar flexion contracture, the pre-treatment passive range of motion must be measured with a goniometer and documented in the medical record. There must be documentation of an appropriate stretching program carried out by professional staff (in a nursing facility) or caregiver (at home).

Not Medically Necessary:

AFOs and KAFOs are considered not medically necessary if the above criteria are not met and for all other indications, including but not limited to the following:

1. Used solely for the treatment of edema; or
2. Used solely for the prevention or treatment of a heel pressure ulcer: or
3. Used for a fixed contracture.

Walking boots used primarily to relieve pressure, especially on the sole of the foot, or used for individuals with foot ulcers are considered not medically necessary.

A component of a static AFO that is used to address positioning of the knee or hip in a non-ambulatory individual is considered not medically necessary.

A foot drop splint/recumbent positioning device and replacement interface is considered not medically necessary when it is used solely for the prevention or treatment of a heel pressure ulcer because this does not meet the definition of a brace.

A foot drop splint/recumbent positioning device and replacement interface is considered not medically necessary in an individual with foot drop who is non-ambulatory.

Repairs and/or Replacement

Medically Necessary:

Repairs to medically necessary AFOs and KAFOs, due to wear or damage, are considered medically necessary when they are necessary to make the AFO or KAFO functional.

Replacement of an AFO or KAFO or component of an AFO or KAFO due to loss, significant change in the individual’s condition*, or irreparable damage is considered medically necessary if the device is still medically necessary.

* This may include significant growth in a child or adolescent, major weight loss or gain, or other body changes that result in poor prosthetic fit or function.

Not Medically Necessary:

Replacement components (for example, soft interfaces) that are provided on a routine basis without regard to whether the original item is worn out are considered not medically necessary.

This document describes clinical studies and expert recommendations and explains when orthoses for the ankle-foot or the knee-ankle-foot are clinically appropriate. The following summary does not replace the medical necessity criteria or other information in this document. The summary may not contain all of the relevant criteria or information. This summary is not medical advice. Please check with your healthcare provider for any advice about your health.

Key Information

An ankle-foot orthosis (AFO) is a rigid or semi-rigid brace that supports the foot and ankle. A knee-ankle-foot orthosis (KAFO) supports the foot, ankle, and knee. These braces may help improve stability, support weak muscles, limit harmful movement, and improve walking. Some are prefabricated, while others are custom made to fit a person's body. Walking boots are another type of brace that keep the foot or ankle still while it heals after an injury or surgery. Studies suggest these braces can improve walking and balance for some people, although benefits vary depending on the person's condition. Some custom braces may be needed for people with complex medical needs.

What the Studies Show

AFOs and KAFOs are used to support weak muscles, improve stability, and help people move more safely. Clinical practice guidelines from the American Physical Therapy Association (APTA) and the Academy of Neurologic Physical Therapy (ANPT) report that AFOs can improve walking speed, mobility, and balance after a stroke. Studies also suggest they may improve quality of life, walking endurance, and muscle activity for some people. Research has not shown that AFOs reduce muscle tightness caused by stroke. Studies comparing AFOs with functional electrical stimulation (FES) have not shown that one treatment is always better than the other. The most appropriate option may change over time, so regular reassessment is important.

Studies also show that AFOs can improve walking in children with cerebral palsy. Results in people who have had a stroke have been mixed, with some studies showing improved walking and others finding little or no improvement for certain walking tests. For people with neuromuscular disorders, a small number of studies suggest AFOs may improve walking speed and satisfaction. Better studies are needed to know if AFOs improve walking effort or balance in this group. Possible disadvantages include discomfort, the need for proper fitting, and the possibility that the brace may need adjustment or replacement if a person's condition changes.

When are Ankle-Foot Orthoses , Knee-Ankle-Foot Orthoses , and Walking Boots Clinically Appropriate?

These devices may be appropriate in the following situations:

• An AFO may be appropriate for a person who is able to walk, either independently or with help, and has weakness or a deformity of the foot or ankle that needs medical stabilization, and the brace is expected to improve function.
• A KAFO may be appropriate for a person who is able to walk when an AFO is appropriate and extra knee stability is needed.
• A custom-fabricated AFO or KAFO may be appropriate when the usual medical criteria are met and one or more of the following applies:
  • A prefabricated brace cannot provide an appropriate fit.
  • The condition is expected to last longer than 6 months.
  • The brace must control movement in more than one direction.
  • A neurological, circulatory, or orthopedic condition requires a custom fit to help prevent injury to the skin or other tissues.
  • A healing fracture has changed the normal shape of the limb.
• A walking boot may be appropriate to keep the foot or ankle still while an orthopedic condition heals or after orthopedic surgery.
• A static AFO may be appropriate for a person who is not able to walk when all of the following apply:
  • The ankle has a non-fixed plantar flexion contracture with at least 10 degrees of passive movement.
  • There is a reasonable expectation that treatment can correct the contracture or prevent it from becoming fixed if the person later becomes able to walk.
  • The contracture interferes with, or is expected to interfere with, daily function.
  • The brace is part of a therapy program that includes passive stretching of the affected muscles or tendons.

When is this not Clinically Appropriate?

The following uses are not considered clinically appropriate because they are not included in the clinical indications described above. The Discussion section summarizes research on the benefits of AFOs for certain walking conditions, but it does not provide studies showing that these other uses improve health.

• Using an AFO or KAFO only to treat swelling (edema).
• Using an AFO or KAFO only to prevent or treat a heel pressure ulcer.
• Using an AFO for a fixed contracture.
• Using an AFO for foot drop when there is no ankle flexion contracture.
• Using a walking boot mainly to reduce pressure on the bottom of the foot or to treat foot ulcers.
• Using part of a static AFO only to position the knee or hip in a person who is not able to walk.
• Using a foot drop splint or recumbent positioning device only to prevent or treat a heel pressure ulcer because it does not meet the definition of a brace.
• Using a foot drop splint or recumbent positioning device for foot drop in a person who is not able to walk.

Better studies are needed to know if these uses improve health. Unnecessary or unproven braces can lead to needless worry, or to treatment that does not help.

AFOs, KAFOs, walking boots, and related devices are not clinically appropriate in situations other than those listed above.

Repairs and Replacement

Repairs to medically necessary AFOs or KAFOs may be appropriate when they are needed to restore the function of the brace. Replacement of a medically necessary brace or one of its parts may be appropriate if it is lost, damaged beyond repair, or no longer fits because of a major change in the person's condition, such as growth in a child, major weight change, or another body change, and the brace is still medically necessary.

Replacing parts on a routine schedule, without showing that the original part is worn out, is not clinically appropriate.

(Return to Description)

The following codes for treatments and procedures applicable to this document are included below for informational purposes. Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When services may be Medically Necessary when criteria are met:

Associated Coding

When services may also be Medically Necessary for associated, secondary or subsequent replacement components when the AFOs and KAFOs meet criteria:

When services are Not Medically Necessary:
For the procedure codes listed above when criteria are not met or for situations designated in the Clinical Indications section as not medically necessary.

Summary

Ankle-foot orthoses (AFOs), unlike foot orthoses, extend above the ankle and can extend to near the top of the calf. Knee-ankle-foot-orthoses (KAFOs) extend from the upper portion of the thigh to the toes, crossing the knee and ankle. Clinical guidelines from the American Physical Therapy Association (APTA) and the Academy of Neurologic Physical Therapy (ANPT) state that both AFOs and functional electrical stimulation (FES) improve gait speed, mobility, and balance post-stroke, and there is some support for enhancements in quality of life and muscle activation. Meta-analyses have found that AFOs improve walking outcomes in ambulatory children with cerebral palsy and provide mixed results in stroke survivors. Limited evidence in individuals with neuromuscular disorders suggests AFOs may improve walking speed and satisfaction, though effects on walking effort and balance remain unclear.

Discussion

A non-ambulatory AFO may be either an ankle contracture splint or a foot drop splint.

A static AFO is an ankle-foot orthosis that has all of the following characteristics:

1. Designed to accommodate an ankle with a plantar flexion contracture up to 45^○; and
2. Applies a dorsiflexion force to the ankle; and
3. Allows pressure reduction; and
4. Has a soft interface.

A foot drop splint/recumbent positioning device is a prefabricated ankle-foot orthosis that has all of the following characteristics:

1. Designed to maintain the foot at a fixed position of zero degrees (that is, perpendicular to the lower leg); and
2. Not designed to accommodate an ankle with a plantar flexion contracture; and
3. Used by an individual who is non-ambulatory; and
4. Has a soft interface.

A clinical practice guideline published in 2021 from the APTA and the ANPT, addressed AFO and FES post-stroke. Based on a review of published literature, the guideline had the following conclusions:

Strong evidence exists that AFO and FES can each increase gait speed, mobility, and dynamic balance. Moderate evidence exists that AFO and FES increase quality of life, walking endurance, and muscle activation, and weak evidence exists for improving gait kinematics. AFO or FES should not be used to decrease plantarflexor spasticity. Studies that directly compare AFO and FES do not indicate overall superiority of one over the other. But evidence suggests that AFO may lead to more compensatory effects while FES may lead to more therapeutic effects. Due to the potential for gains at any phase post-stroke, the most appropriate device for an individual may change, and reassessments should be completed to ensure the device is meeting the individual’s needs.

Meta-analyses of published literature have found that AFOs significantly improve walking-related outcome measures (that is, walking speed, stride length and timed walking distance) in ambulatory children with cerebral palsy (Betancourt, 2019; Lintanf, 2018). Meta-analyses have had mixed findings regarding the impact of AFOs on individuals who have had strokes. Several meta-analyses (Choo, 2021, Nascimento, 2020; Prenton, 2020) found positive impacts of AFOs on walking outcomes in individuals after stroke. However, Shahabi (2020) did not find a significant positive impact of AFOs on walking speed in individuals after stroke, and Daryabor (2021) did not find that AFO use significantly improved results of the 6-minute walking or Time up-Stairs tests. A 2025 Cochrane meta-analysis identified a limited number of small studies on AFOs in individuals with calf muscle weakness due to neuromuscular disorders and, based on this evidence, the investigators concluded that AFOs might lead to increased walking speed and satisfaction, and that conclusions could not be drawn on the impact of AFOs on walking effort or balance in this population.

Ankle flexion contracture: A condition in which there is shortening of the muscles or tendons that plantar-flex the ankle with the resulting inability to bring the ankle to zero degrees by passive range of motion (zero degrees ankle position is when the foot is perpendicular to the lower leg).

Ankle-foot orthoses (AFOs): These extend well above the ankle (usually to near the top of the calf) and are fastened around the lower leg above the ankle. These features distinguish them from foot orthoses which are shoe inserts that do not extend above the ankle.

Custom-fabricated orthosis: An orthosis that is individually made for a specific individual starting with basic materials including, but not limited to, plastic, metal, leather, or cloth in the form of sheets, bars, etc. The process involves substantial work such as cutting, bending, molding, sewing, etc. It may involve the incorporation of some prefabricated components, and it involves more than trimming, bending, or making other modifications to a substantially prefabricated item.

Foot drop: A condition in which there is weakness or lack of use of the muscles that dorsiflex the ankle, but there is the ability to bring the ankle to zero degrees by passive range of motion.

Knee-ankle-foot-orthoses (KAFOs): An orthosis designed to control knee and ankle motion that extends from the upper portion of the thigh, crossing the knee and ankle and ending at the toes.

Orthosis (brace): A rigid or semi-rigid device that is used for the purpose of supporting a weak or deformed body part, or for restricting or eliminating motion in a diseased or injured part of the body. An orthosis can be either prefabricated or custom-fabricated.

Prefabricated orthosis: An orthosis that is manufactured in quantity without a specific individual in mind. A prefabricated orthosis may be trimmed, bent, molded (with or without heat), or otherwise modified for use by a specific individual (that is, custom fitted). An orthosis that is assembled from prefabricated components is considered prefabricated. Any orthosis that does not meet the definition of a custom-fabricated orthosis is considered prefabricated.

Peer Reviewed Publications:

1. Betancourt JP, Eleeh P, Stark S, et al. Impact of Ankle-foot orthosis on gait efficiency in ambulatory children with cerebral palsy: a systematic review and meta-analysis. Am J Phys Med Rehabil. 2019; 98(9):759-770.
2. Choo YJ, Chang MC. Effectiveness of an ankle-foot orthosis on walking in patients with stroke: a systematic review and meta-analysis. Sci Rep. 2021; 11(1):15879.
3. Daryabor A, Kobayashi T, Yamamoto S, et al. Effect of ankle-foot orthoses on functional outcome measurements in individuals with stroke: a systematic review and meta-analysis. Disabil Rehabil. 2022; 44(22):6566-6581.
4. Lintanf M, Bourseul JS, Houx L, et al. Effect of ankle-foot orthoses on gait, balance and gross motor function in children with cerebral palsy: a systematic review and meta-analysis. Clin Rehabil. 2018; 32(9):1175-1188.
5. Nascimento LR, da Silva LA, Araújo Barcellos JVM, Teixeira-Salmela LF. Ankle-foot orthoses and continuous functional electrical stimulation improve walking speed after stroke: a systematic review and meta-analyses of randomized controlled trials. Physiotherapy. 2020; 109:43-53.
6. Prenton S, Hollands KL, Kenney LP. Functional electrical stimulation versus ankle foot orthoses for foot-drop: a meta-analysis of orthotic effects. J Rehabil Med. 2016; 48(8):646-656.
7. Shahabi S, Shabaninejad H, Kamali M, et al. The effects of ankle-foot orthoses on walking speed in patients with stroke: a systematic review and meta-analysis of randomized controlled trials. Clin Rehabil. 2020; 34(2):145‐159.

Government Agency, Medical Society, and Other Authoritative Publications:

1. CGS Administrators, LLC and Noridian Healthcare Solutions, LLC. Local Coverage Determination for Ankle-Foot/Knee-Ankle-Foot Orthosis (L33686). Effective 1/1/2020. Available at: https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?LCDId=33686. Accessed on June 30, 2026.
2. Johnston TE, Keller S, Denzer-Weiler C, et al. A clinical practice guideline for the use of ankle-foot orthoses and functional electrical stimulation post-stroke. J Neurol Phys Ther. 2021; 45(2):112-196.
3. van Duijnhoven E, Waterval NF, Koopman FS, et al. Ankle-foot orthoses for improving walking in adults with calf muscle weakness due to neuromuscular disorders. Cochrane Database Syst Rev. 2025; 1(1):CD014871.

Ankle-Foot Orthosis
Knee-Ankle-Foot Orthosis
Stance control knee brace

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