About ICD10Source

Why I Built This

My name is Omar Santaella. I am an X-ray technologist with over a decade of hands-on experience in healthcare, including medical billing and coding. I have spent years working alongside coders, billers, and revenue cycle teams — and I have seen firsthand how fragmented the available tools are.

Medical coders constantly switch between multiple resources to find what they need for a single code — one tool for the description, another for CC/MCC flags, another for HCC categories, and yet another for sequencing rules. Many of these tools are also locked behind expensive paywalls and subscription fees that small practices and individual coders cannot easily afford.

I built ICD10Source to fix that. Every clinical flag a working coder needs is displayed alongside the code itself — in one place, instantly, and completely free. I created this site to make my own job better and to help others in the field do the same. Information that should be accessible to everyone in healthcare should not be hidden behind a paywall.

The tool uses only official CMS and CDC public domain datasets, with no proprietary or third-party data.

What ICD10Source Provides

ICD10Source is not a replacement for the official ICD-10-CM code book or certified coding guidance. It is a fast, free reference tool designed to support coders during their daily work. Features include:

• 102,885 ICD-10-CM diagnosis codes from the official CMS Section 111 Valid ICD-10 FY2026 dataset, effective October 1, 2025
• CC/MCC flags — 1,071 Complication or Comorbidity codes and 333 Major Complication or Comorbidity codes from the CMS FY2026 IPPS Final Rule
• HCC categories and RAF scores — 260 codes mapped to Hierarchical Condition Categories under CMS-HCC Model V28
• POA indicators — 8,071 Present on Admission exempt codes flagged
• Diagnosis sequencing rules — Additional Only, First-Listed Only, and Etiology First flags
• Age and sex restrictions — Newborn, Pediatric, Maternity, Adult, Female Only, and Male Only coding restrictions
• ICD-9 to ICD-10 crosswalk — bidirectional GEM mappings with exact vs approximate notation
• Multi-code export — copy as list, codes only, or CSV
• Printable code sheets — with all clinical flags included

Data Sources

All data used in ICD10Source is sourced from official U.S. government publications in the public domain. No proprietary or third-party data is used.

For complete information about data accuracy and limitations, please review our Disclaimer.

Site Statistics

Important Disclaimer

ICD10Source is a reference tool for informational purposes only. It is not a substitute for professional medical advice, clinical judgment, certified coding guidance, or official CMS publications. Always verify codes against the most current official sources before use in billing or clinical documentation.

For complete terms, see our full Disclaimer and Privacy Policy.

Official Resources & Further Reading

ICD10Source is built on official U.S. government public domain data. For authoritative coding guidance, always refer to these primary sources:

• CMS ICD-10 Codes & Resources — Official CMS page for ICD-10-CM codes, guidelines, and annual updates
• CDC ICD-10-CM Official Guidelines — Annual coding guidelines published by the CDC and NCHS
• CMS IPPS Final Rule — Source for CC/MCC designations updated annually
• CMS HCC Risk Adjustment Model — CMS-HCC Model V28 documentation
• AAPC — The largest medical coding credentialing organization in the US
• AHIMA — American Health Information Management Association

Contact Us

For questions, feedback, data issue reports, or advertising inquiries, please visit our Contact page.