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ICD-10 Guide
ICD-10 CodesM46.91

M46.91

Billable

Unspecified inflammatory spondylopathy, occipito-atlanto-axial region

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

Code Description

ICD-10 M46.91 is a billable code used to indicate a diagnosis of unspecified inflammatory spondylopathy, occipito-atlanto-axial region.

Key Diagnostic Point:

Unspecified inflammatory spondylopathy in the occipito-atlanto-axial region refers to a condition characterized by inflammation of the spine, particularly affecting the junction between the occipital bone at the base of the skull and the first two cervical vertebrae (the atlas and axis). This condition can lead to pain, stiffness, and reduced mobility in the neck. Inflammatory spondylopathies encompass a range of disorders, including ankylosing spondylitis, which is a chronic inflammatory disease primarily affecting the axial skeleton. The occipito-atlanto-axial region is critical for head movement and stability, and inflammation here can significantly impact a patient's quality of life. Symptoms may include neck pain, headaches, and neurological deficits if the spinal cord is compressed. Diagnosis typically involves clinical evaluation, imaging studies, and sometimes laboratory tests to identify inflammatory markers. Treatment often includes anti-inflammatory medications, physical therapy, and in some cases, surgical intervention. Accurate coding is essential for appropriate management and reimbursement.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variability in clinical presentation and symptoms
  • Need for comprehensive documentation to support diagnosis
  • Differentiation from other spondylopathies and spinal conditions
  • Potential overlap with other inflammatory diseases

Audit Risk Factors

  • Insufficient documentation of inflammatory markers
  • Lack of imaging studies to support diagnosis
  • Inconsistent clinical notes regarding symptoms
  • Failure to specify the location of inflammation

Specialty Focus

Medical Specialties

Rheumatology

Documentation Requirements

Detailed clinical history, physical examination findings, imaging results, and laboratory tests.

Common Clinical Scenarios

Patients presenting with chronic neck pain, stiffness, and inflammatory markers.

Billing Considerations

Ensure clear documentation of inflammatory symptoms and response to treatment.

Orthopedics

Documentation Requirements

Surgical notes, imaging studies, and pre-operative assessments.

Common Clinical Scenarios

Patients requiring surgical intervention for severe spinal stenosis or instability.

Billing Considerations

Document the rationale for surgical intervention and any conservative treatments attempted.

Coding Guidelines

Inclusion Criteria

Use M46.91 When
  • Follow official ICD
  • 10 guidelines for coding inflammatory spondylopathies
  • Ensure that the diagnosis is supported by clinical findings and imaging

Exclusion Criteria

Do NOT use M46.91 When
  • Exclude other specific conditions that may better describe the patient's symptoms

Related ICD-10 Codes

Related CPT Codes

72148CPT Code

Magnetic resonance imaging (MRI) of the cervical spine

Clinical Scenario

Used to evaluate inflammatory changes in the occipito-atlanto-axial region.

Documentation Requirements

Indication for MRI must be clearly documented, including symptoms and prior treatments.

Specialty Considerations

Rheumatologists and orthopedic surgeons should ensure imaging correlates with clinical findings.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of inflammatory spondylopathies, improving the accuracy of diagnoses and treatment tracking. M46.91 provides a means to capture unspecified cases, but coders should strive for specificity when possible.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of inflammatory spondylopathies, improving the accuracy of diagnoses and treatment tracking. M46.91 provides a means to capture unspecified cases, but coders should strive for specificity 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 is the difference between M46.91 and M46.90?

M46.91 specifies inflammatory spondylopathy in the occipito-atlanto-axial region, while M46.90 is a more general code for unspecified inflammatory spondylopathy without a specified site.