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v1.0.0
ICD-10 Guide
ICD-10 CodesM21.959

M21.959

Billable

Unspecified acquired deformity of unspecified thigh

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/17/2025

Code Description

ICD-10 M21.959 is a billable code used to indicate a diagnosis of unspecified acquired deformity of unspecified thigh.

Key Diagnostic Point:

M21.959 refers to an unspecified acquired deformity of the thigh, which can arise from various causes such as trauma, surgery, or underlying medical conditions. Acquired deformities may manifest as changes in bone structure, alignment, or soft tissue, leading to functional impairment or aesthetic concerns. Common examples include deformities resulting from fractures that heal improperly, post-surgical changes, or conditions like osteoarthritis that alter the normal anatomy of the thigh. The thigh is a critical area for mobility, and deformities can significantly impact a patient's quality of life, leading to pain, difficulty in ambulation, and increased risk of falls. Treatment options may vary widely, from conservative management such as physical therapy to surgical interventions aimed at correcting the deformity. Accurate coding is essential for appropriate reimbursement and to reflect the complexity of the patient's condition.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Lack of specificity in the diagnosis
  • Variability in underlying causes of deformity
  • Potential for multiple associated conditions
  • Need for detailed clinical documentation to support the diagnosis

Audit Risk Factors

  • Insufficient documentation of the deformity's cause
  • Inconsistent terminology used in clinical notes
  • Lack of follow-up documentation to support ongoing treatment
  • Failure to specify the laterality of the deformity

Specialty Focus

Medical Specialties

Orthopedics

Documentation Requirements

Detailed clinical notes describing the deformity, its cause, and impact on function.

Common Clinical Scenarios

Post-fracture deformities, post-surgical changes, or deformities due to degenerative conditions.

Billing Considerations

Ensure that all relevant imaging and diagnostic tests are documented to support the diagnosis.

Physical Medicine and Rehabilitation

Documentation Requirements

Comprehensive assessment of functional limitations and treatment plans.

Common Clinical Scenarios

Rehabilitation following orthopedic surgery or trauma.

Billing Considerations

Focus on the impact of the deformity on mobility and quality of life.

Coding Guidelines

Inclusion Criteria

Use M21.959 When
  • Follow the official ICD
  • CM coding guidelines, ensuring that the diagnosis is supported by clinical documentation
  • The code should be used when the specific cause of the acquired deformity is not documented
  • If the cause is known, a more specific code should be selected

Exclusion Criteria

Do NOT use M21.959 When
No specific exclusions found.

Related ICD-10 Codes

Related CPT Codes

27447CPT Code

Osteotomy, femur

Clinical Scenario

Used for surgical correction of acquired deformities of the thigh.

Documentation Requirements

Surgical notes detailing the procedure and indication for surgery.

Specialty Considerations

Orthopedic surgeons should ensure that the deformity is well-documented to justify the procedure.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more detailed coding of acquired deformities, enabling better tracking of treatment outcomes and resource allocation. M21.959 provides a mechanism to capture cases where the specifics of the deformity are not fully documented, although it is essential to strive for more precise coding when possible.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more detailed coding of acquired deformities, enabling better tracking of treatment outcomes and resource allocation. M21.959 provides a mechanism to capture cases where the specifics of the deformity are not fully documented, although it is essential to strive for more precise coding when possible.

Reimbursement & Billing Impact

reimbursement.

Resources

Clinical References

  • •
    ICD-10-CM Official Guidelines for Coding and Reporting

Coding & Billing References

  • •
    ICD-10-CM Official Guidelines for Coding and Reporting

Frequently Asked Questions

What should I document to support the use of M21.959?

Document the clinical findings, the cause of the deformity if known, and the impact on the patient's function. Include any imaging studies or assessments that support the diagnosis.