What is the ICD-10 code for drop foot?

The ICD-10 code for drop foot is M21.371 for the right foot and M21.372 for the left foot. These codes are used when the foot drop is acquired and not due to a congenital condition.

How do you code foot drop with a known cause?

When foot drop is due to a known cause, code the underlying condition first, such as G57.3 for peroneal nerve injury, followed by the appropriate M21.37x code for laterality.

ICD-10 Coding for Drop Foot(M21.371, G57.3, M21.37)

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Explore detailed ICD-10 coding guidelines for drop foot, including primary and secondary codes, documentation requirements, and common coding pitfalls.

Also known as:

Foot DropPeroneal Nerve PalsySteppage Gait

Related ICD-10 Code Ranges

Complete code families applicable to Drop Foot

M00-M99Primary Range

Diseases of the musculoskeletal system and connective tissue

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Code Comparison: When to Use Each Code

Compare key differences between these codes to ensure accurate selection

Code	Description	When to Use	Key Documentation
M21.371	Foot drop, right foot	Use when foot drop is present in the right foot without a specified underlying cause.	Clinical examination showing inability to dorsiflex the right foot. Muscle strength grading (0-5 scale) indicating weakness.
M21.372	Foot drop, left foot	Use when foot drop is present in the left foot without a specified underlying cause.	Clinical examination showing inability to dorsiflex the left foot. Muscle strength grading (0-5 scale) indicating weakness.

Primary ICD-10-CM Codes

Foot drop, right foot

M21.371Billable

Differential Codes

Alternative codes to consider when ruling out similar conditions

Lesion of lateral popliteal nerveG57.3

Use when EMG/NCS confirms peroneal nerve involvement.

Documentation & Coding Risks

Avoid these common issues when documenting Drop Foot.

Failing to document the underlying cause of foot drop.

Impact

Clinical: Inaccurate diagnosis and treatment planning., Regulatory: Non-compliance with coding standards., Financial: Potential claim denials or reduced reimbursement.

Mitigation

Thorough clinical evaluation., Detailed documentation of diagnostic findings.

Using M21.37x without specifying laterality.

Impact

Reimbursement: Incorrect coding can lead to claim denials., Compliance: Non-compliance with ICD-10 coding guidelines., Data Quality: Inaccurate clinical data affecting patient records.

Mitigation

Ensure documentation specifies whether the right or left foot is affected.

Laterality Documentation

Impact

Risk of audit due to unspecified laterality in foot drop cases.

Mitigation

Implement mandatory laterality checks in clinical documentation.

Frequently Asked Questions

Documentation requirements, coding pitfalls and FAQs for conditions coded with M21.371.

Primary Code

M21.371

Foot drop, right foot

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ICD-10 codes6

Coding risks3

FAQs2

ICD-10 Coding for Drop Foot(M21.371, G57.3, M21.37)

Documentation & Coding Risks

Frequently Asked Questions

What is the ICD-10 code for drop foot?

How do you code foot drop with a known cause?

Related condition guides