Podiatry Coding & Billing Alert

Is there a single code for flat feet correction?

Flat feet — clinically referred to as pes planus — are among the most documented conditions in podiatry practices. Despite their frequency, flat feet remain a consistent source of billing confusion. For podiatry coders and billers, the challenge lies in understanding that the diagnosis alone rarely supports covered services. Correct coding depends on symptom severity, functional impact, and payer-specific coverage rules.

Continue reading to learn how to correctly report flat feet diagnosis and procedures.

Understand Pes Planus for Podiatry Coding

Pes planus describes partial or complete collapse of the medial longitudinal arch. The condition may be congenital or acquired and may present as flexible or rigid. From a billing perspective, the clinical appearance of the foot is less important than whether the condition is symptomatic and medically significant.

Many patients have flat feet without pain or limitation. In these cases, pes planus is generally considered a normal anatomical variant rather than a condition requiring medical treatment. Payers focus on whether the patient experiences pain, instability, progressive deformity, or functional impairment affecting movement or daily activities.

Identify Flat Feet ICD-10-CM Codes

You’ll assign an appropriate code from the M21.4- (Flat foot [pes planus] (acquired)) code subcategory to report flat feet diagnoses for most podiatry encounters, with the 5^th character representing the laterality. On the other hand, congenital flat foot is reported with Q66.5- (Congenital pes planus) codes and is less applicable in adult podiatry.

Payers often deny pes planus claims due to missing supporting documentation of symptoms. Chart notes should clearly connect the diagnosis to pain, difficulty walking, tendon dysfunction, or secondary conditions. When flat feet contribute to other pathologies, such as posterior tibial tendon dysfunction or plantar fasciitis, those conditions should also be documented and coded when supported.

Examine Evaluation and Management Codes

You’ll report an evaluation and management (E/M) service when the provider is evaluating or managing a symptomatic condition, not simply noting foot structure.

Common billable scenarios include:

• New patient evaluations for painful or worsening flat feet
• Established patients with progression of symptoms
• Failure of conservative treatment requiring a change in care

Documentation should support medical decision making (MDM), including an assessment of severity, a review of prior treatments, and a rationale for the treatment plan. When the podiatrist performs an E/M on the same date as a procedure, you’ll report it with modifier 25 (Significant, separately identifiable evaluation and management service by the same physician or other qualified health care professional on the same day of the procedure or other service) appended if the E/M is significant, separately identifiable, and well documented.

Recognize Procedure Codes Commonly Associated With Flat Feet

There is no single CPT^® code for treating flat feet. The coding is based on the services performed.

Orthotics and bracing: Custom foot orthotics are commonly associated with pes planus. You’ll use HCPCS Level II code L3000 (Foot, insert, removable, molded to patient model, 'UCB' type, Berkeley Shell, each) to report orthotics in most cases. Medicare considers routine foot orthotics statutorily noncovered when used solely for structural support, even when medically recommended. Only those attached to a covered ankle brace are covered. You can provide the patient with an advance beneficiary notice (ABN) so the patient understands out-of-pocket responsibility. Commercial payer coverage varies and should be verified in advance.

Imaging: You may report foot X-rays when the imaging is medically necessary to evaluate pain, deformity, or suspected progression. Payers may deny claims for imaging performed without a documented clinical indication.

Ancillary services: Physical therapy referrals may be appropriate. However, informal gait evaluations performed in the office are generally not separately billable.

Memorize Medicare Rules for Flat Feet

Medicare coverage adds another layer of complexity. Many Medicare Administrative Contractors (MACs), including First Coast Service Options (FCSO), process flat feet-related services under the broader routine foot care exclusion framework.

Under Medicare policy, services or devices directed at flat feet care or correction are generally considered noncovered routine foot care, unless medical necessity criteria are clearly met. Flat feet without significant symptoms or functional impairment are typically viewed as structural or maintenance conditions rather than treatable medical problems.

This means that services such as an E/M visit for nonsymptomatic flat feet are commonly denied unless the documentation demonstrates that treatment is addressing pain, functional limitation, or an associated covered condition. Simply including the diagnosis code for flat feet on the claim will often result in a denial. Coverage isn’t based on the diagnosis alone, but on the presence of medically necessary treatment for a specific clinical problem.

Consider These Surgical Codes

There is no single CPT^® code for flat foot correction. Surgical treatment of pes planus is most often coded based on the specific anatomical structures addressed, not the diagnosis itself. Flat foot reconstruction is typically a multi-procedure surgery, and accurate coding relies heavily on the operative report.

Common procedure categories include:

• Osteotomies: These are procedures to realign the hindfoot or midfoot, such as calcaneal or tarsal osteotomies.
• Tendon repairs or transfers: These procedures frequently involve the posterior tibial tendon (for example, tendon repair or flexor digitorum longus transfer).
• Arthrodesis: Surgeons perform these procedures for rigid or advanced deformities, including subtalar, talonavicular, or triple arthrodesis.
• Soft-tissue procedures: These procedures can include gastrocnemius recession or Achilles tendon lengthening and are performed to address contributing contractures.

Coders should note that these procedures aren’t inherently bundled simply because they’re performed for flat foot correction. Each procedure must be supported by clear documentation describing the pathology addressed and the surgical intent. You must carefully review laterality, distinct procedural components, and National Correct Coding Initiative (NCCI) edits to ensure proper reporting and modifier use when appropriate.

As with nonsurgical management, pes planus alone doesn’t establish medical necessity for surgery. The podiatrist’s documentation should demonstrate pain, functional limitation, progression of deformity, and failure of conservative treatment to support coverage.

Learn How to Avoid Common Types of Denials

Claim denials related to flat feet commonly include:

• Not medically necessary
• Services categorized as routine foot care
• Orthotics listed as noncovered
• Inadequate documentation of symptoms or functional impairment

Billers can reduce denials by ensuring that the documentation clearly supports medical necessity, the diagnosis-to-procedure link is accurate, and coverage policies are reviewed before claim submission.

Review This Final Takeaway

Flat feet are common, but reimbursement for covered services related to pes planus isn’t automatic. Successful coding depends on understanding that structure alone doesn’t establish medical necessity. Clear documentation, appropriate diagnosis selection, and awareness of Medicare and payer coverage rules are critical.

For podiatry coders and billers, mastering the nuances of pes planus coding helps protect compliance while supporting appropriate reimbursement, which can turn a frequently documented condition into a correctly reported one.

Tonia Silva, CPC, CPMA, CPPM, Contributing Writer