ICD-10 Coding for Breast Cancer (C50.911): Right Female Breast

Updated on: July 23, 2025

Breast cancer remains one of the most commonly diagnosed cancers worldwide. The ICD-10 code C50.911 is used to document malignant neoplasm of an unspecified site in the right female breast when site-specific detail (e.g., upper-outer quadrant) is not available or not documented.

ICD-10 Code Breakdown: C50.911

• C50 → Malignant neoplasm of the breast

• .9 → Unspecified site in the breast

• .1 → Right breast

• 1 → Female

🚨 Note: If the tumor location is known (e.g., upper inner quadrant), use a more specific code such as C50.211.

Common Breast Cancer Sites and Their Codes

When to Use C50.911

Use C50.911 when:

• Patient has a confirmed diagnosis of breast cancer

• The affected breast is right

• The exact site within the breast is not specified

• Patient is female (for male, use C50.911 with sex modifier or male-specific site)

Clinical Documentation Elements Required

To assign C50.911 properly, include the following in your documentation:

• Laterality: Right vs Left

• Confirmation of malignancy (via biopsy or imaging)

• Absence of site detail (justifies unspecified code)

• Histology subtype if available (e.g., ductal carcinoma)

• Stage/grade (TNM classification)

Example of Complete Documentation:

“Female patient diagnosed with invasive ductal carcinoma of the right breast. Site within breast not specified in current imaging. Awaiting pathology report. Initiating hormonal therapy.”

How to Improve Specificity and Avoid C50.911

Coders and clinicians are encouraged to avoid unspecified codes when possible. Use more specific C50 codes by documenting:

• Tumor location (e.g., nipple, central, upper outer)

• Pathology details (invasive ductal, lobular, etc.)

• Lymph node involvement (C77.3 if axillary)

This not only supports precision in care but also improves risk adjustment scores, cancer registry reporting, and treatment planning.

Commonly Paired ICD-10 Codes

Treatment and Workflow Considerations

Once breast cancer is diagnosed and coded:

• Initiate oncology referral

• Conduct imaging (mammogram, MRI, PET/CT)

• Evaluate hormone receptor status (ER, PR, HER2)

• Consider surgical planning (lumpectomy, mastectomy)

• Document treatment intent (curative vs palliative)

Virtual scribes like DocScrib ensure that these workflows are automatically captured and properly coded for streamlined care coordination.

How DocScrib Supports Breast Cancer Documentation

With complex oncology cases like breast cancer, DocScrib’s AI medical scribe can:

• Auto-detect laterality and site details from provider dictation

• Flag unspecified site use (C50.911) for CDI review

• Track progress notes and pathology reports

• Integrate with EHR templates for TNM staging and treatment plans

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Reimbursement & Risk Adjustment Considerations

• C50.911 is a Hierarchical Condition Category (HCC) diagnosis, impacting RAF scores in value-based care.

• Inaccurate use of unspecified codes may reduce reimbursement or trigger chart reviews.

• Stage documentation impacts coding specificity, oncology approvals, and registry submissions.

Frequently Asked Questions

Should I use C50.911 if the breast cancer site is unknown at the time of visit?
Yes, but update to a more specific code once location is confirmed.

Can C50.911 be used for male breast cancer?
Technically yes, but you should specify the sex and consider using male-specific breast cancer codes (like C50.911 + gender indicator or use C50.911 with documentation stating male breast).

What if both breasts are involved?
Use bilateral codes if site is known (e.g., C50.919) or code each side separately with specific tumor sites.

Conclusion

ICD-10 Code C50.911 serves as a placeholder for right-sided female breast cancer when tumor location is unspecified. While useful in initial documentation stages, clinicians and coders should aim for higher specificity once pathology results or imaging data are available. Leveraging AI-powered scribe tools like DocScrib ensures nothing gets missed in this critical documentation and billing process.

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