ICD-10 Logo
ICDxICD-10 Medical Coding
ICD-10 Logo
ICDxICD-10 Medical Coding
ICD 10 CodesDiagnoses
ICD 10 CodesDiagnoses
ICD-10 Logo
ICDxICD-10 Medical Coding

Comprehensive ICD-10-CM code reference with AI-powered search capabilities.

© 2025 ICD Code Compass. All rights reserved.

Browse

  • All Chapters
  • All Categories
  • Diagnoses

Tools

  • AI Code Search
ICD-10-CM codes are maintained by the CDC and CMS. This tool is for reference purposes only.
v1.0.0
ICD-10 Guide
ICD-10 CodesM66.9

M66.9

Billable

Spontaneous rupture of unspecified tendon

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

Code Description

ICD-10 M66.9 is a billable code used to indicate a diagnosis of spontaneous rupture of unspecified tendon.

Key Diagnostic Point:

Spontaneous rupture of a tendon refers to the sudden tearing of a tendon without any apparent external trauma. This condition can occur in various tendons throughout the body, often associated with underlying conditions such as chronic inflammation, degeneration, or systemic diseases. The most commonly affected tendons include those in the shoulder (e.g., rotator cuff), Achilles tendon, and biceps tendon. Patients may present with acute pain, swelling, and loss of function in the affected area. Diagnosis typically involves a thorough clinical examination and imaging studies, such as ultrasound or MRI, to confirm the rupture and assess the extent of the injury. Treatment options may vary from conservative management, including rest and physical therapy, to surgical intervention for complete ruptures. The spontaneous nature of the rupture often complicates the clinical picture, as it may be mistaken for other acute injuries, necessitating careful evaluation and documentation to ensure accurate coding and appropriate management.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variability in clinical presentation and underlying causes
  • Need for precise documentation of the spontaneous nature of the rupture
  • Differentiation from traumatic tendon ruptures
  • Potential for co-existing conditions affecting tendon health

Audit Risk Factors

  • Inadequate documentation of the spontaneous nature of the rupture
  • Failure to specify the affected tendon when possible
  • Misclassification as a traumatic rupture
  • Lack of imaging documentation to support the diagnosis

Specialty Focus

Medical Specialties

Orthopedics

Documentation Requirements

Detailed clinical notes including mechanism of injury, imaging results, and treatment plan.

Common Clinical Scenarios

Patients presenting with acute shoulder pain, sudden onset of weakness in the arm, or calf pain after minimal activity.

Billing Considerations

Ensure clear documentation of the spontaneous nature and any underlying conditions contributing to tendon degeneration.

Rheumatology

Documentation Requirements

Comprehensive assessment of systemic conditions that may predispose to tendon rupture, including lab results.

Common Clinical Scenarios

Patients with autoimmune disorders presenting with tendon pain and swelling.

Billing Considerations

Document any relevant systemic conditions that may affect tendon integrity.

Coding Guidelines

Inclusion Criteria

Use M66.9 When
  • Follow official ICD
  • CM coding guidelines, ensuring accurate documentation of the spontaneous nature of the rupture
  • Include any relevant imaging studies and treatment plans in the medical record

Exclusion Criteria

Do NOT use M66.9 When
No specific exclusions found.

Related ICD-10 Codes

Related CPT Codes

29827CPT Code

Arthroscopy, shoulder, surgical; with repair of a torn rotator cuff

Clinical Scenario

Used when surgical intervention is required for a spontaneous rotator cuff rupture.

Documentation Requirements

Operative report detailing the procedure and findings.

Specialty Considerations

Orthopedic documentation must include pre-operative assessments and post-operative care plans.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of tendon injuries, including spontaneous ruptures. This specificity aids in better tracking of outcomes and resource allocation for treatment.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of tendon injuries, including spontaneous ruptures. This specificity aids in better tracking of outcomes and resource allocation for treatment.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for more specific coding of tendon injuries, including spontaneous ruptures. This specificity aids in better tracking of outcomes and resource allocation for treatment.

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 M66.9 and M66.1?

M66.9 refers to spontaneous rupture of an unspecified tendon, while M66.1 specifically denotes spontaneous rupture of the biceps tendon. Accurate coding requires specifying the tendon involved when possible.