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ICD-10 Guide
ICD-10 CodesN63.21

N63.21

Billable

Unspecified lump in the left breast, upper outer quadrant

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/18/2025

Code Description

ICD-10 N63.21 is a billable code used to indicate a diagnosis of unspecified lump in the left breast, upper outer quadrant.

Key Diagnostic Point:

The ICD-10 code N63.21 refers to an unspecified lump located in the upper outer quadrant of the left breast. This code is used when a patient presents with a palpable mass in this specific area, but the nature of the lump—whether benign or malignant—has not yet been determined. Common benign breast conditions that may present as lumps include fibroadenomas, cysts, and fibrocystic changes. In some cases, the lump may be associated with breast hypertrophy or mastitis, particularly if there are accompanying symptoms such as pain or discharge. Imaging studies, such as mammography or ultrasound, are often employed to evaluate the characteristics of the lump and to rule out malignancy. It is crucial for healthcare providers to document the size, consistency, and any associated symptoms of the lump, as well as the results of any imaging studies performed. This thorough documentation aids in accurate coding and ensures appropriate management of the patient's condition.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variability in documentation of lump characteristics
  • Need for differentiation between benign and malignant conditions
  • Potential for overlapping symptoms with other breast conditions
  • Requirement for imaging studies and their interpretation

Audit Risk Factors

  • Inadequate documentation of the lump's characteristics
  • Failure to document imaging results
  • Misclassification of benign vs. malignant lumps
  • Lack of follow-up documentation

Specialty Focus

Medical Specialties

Oncology

Documentation Requirements

Detailed notes on imaging results, biopsy findings, and treatment plans.

Common Clinical Scenarios

Patients presenting with breast lumps requiring further evaluation for malignancy.

Billing Considerations

Ensure clear documentation of any malignancy workup and follow-up care.

Radiology

Documentation Requirements

Comprehensive imaging reports detailing findings and recommendations.

Common Clinical Scenarios

Imaging studies performed to evaluate breast lumps.

Billing Considerations

Accurate coding based on imaging findings is crucial for reimbursement.

Coding Guidelines

Inclusion Criteria

Use N63.21 When
  • According to ICD
  • 10 coding guidelines, N63
  • 21 should be used when the lump's characteristics are not specified
  • Coders should ensure that the documentation supports the diagnosis and that any imaging studies are noted

Exclusion Criteria

Do NOT use N63.21 When
  • Exclusion criteria include cases where the lump is definitively diagnosed as malignant or associated with specific conditions like mastitis

Related ICD-10 Codes

Related CPT Codes

77067CPT Code

Breast ultrasound

Clinical Scenario

Used to evaluate the characteristics of the lump.

Documentation Requirements

Document the indication for the ultrasound and findings.

Specialty Considerations

Radiologists should ensure that imaging findings correlate with clinical documentation.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for greater specificity in coding breast conditions, including the localization of lumps. This specificity aids in better tracking of breast health issues and improves the quality of care provided to patients.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for greater specificity in coding breast conditions, including the localization of lumps. This specificity aids in better tracking of breast health issues and improves the quality of care provided to patients.

Reimbursement & Billing Impact

reimbursement and compliance with payer requirements.

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 when coding N63.21?

Document the characteristics of the lump, any associated symptoms, results of imaging studies, and any follow-up plans.