ICD-10 2026 Updates: Chapter-Wise New, Revised, and Deleted Codes

The ICD-10-CM 2026 updates are here, bringing significant changes for healthcare providers, coders, and medical billing professionals. Effective October 1, 2025, these updates include 487 new diagnosis codes, 38 revised codes, and 28 deleted codes, improving clinical specificity and documentation accuracy. In this blog post, we break down the updates chapter-wise for easy reference.

📌 Why ICD-10 Updates Matter

• Accurate patient diagnosis coding
• Proper billing and reimbursement
• Reflecting the latest medical knowledge
• Capturing social determinants of health (SDOH)

Staying updated ensures compliance with CMS guidelines and reduces claim denials.

📑 Table of Contents

1. Chapter 1: Certain Infectious and Parasitic Diseases
2. Chapter 2: Neoplasms
3. Chapter 3: Diseases of the Blood and Blood-Forming Organs
4. Chapter 4: Endocrine, Nutritional, and Metabolic Diseases
5. Chapter 6: Diseases of the Nervous System
6. Chapter 7: Diseases of the Eye and Adnexa
7. Chapter 12: Diseases of the Skin and Subcutaneous Tissue
8. Chapter 19: Injury, Poisoning, and Certain Other Consequences of External Causes
9. Chapter 21: Factors Influencing Health Status and Contact with Health Services
10. Summary of ICD-10 2026 Updates
11. How Healthcare Providers Can Prepare

🔹 Chapter 1: Certain Infectious and Parasitic Diseases

• New Codes: Infestation by Demodex mites, other acariasis
• Updated Guidelines: Clarifications on coding HIV disease

🔹 Chapter 2: Neoplasms

• New Codes: Malignant inflammatory neoplasm of the breast
• Guideline Updates: Minor changes for chemotherapy and other treatments

🔹 Chapter 3: Diseases of the Blood and Blood-Forming Organs

• New Codes: Leukocyte adhesion deficiency, functional disorders of neutrophils

🔹 Chapter 4: Endocrine, Nutritional, and Metabolic Diseases

• New Codes:
• Type 2 diabetes in remission
• Primary and secondary hyperoxaluria
• Familial hypercholesterolemia
• Lipodystrophy and mitochondrial metabolism disorders

🔹 Chapter 6: Diseases of the Nervous System

• New Codes:
• Primary progressive apraxia of speech
• Relapsing-remitting multiple sclerosis
• Limb girdle muscular dystrophies

🔹 Chapter 7: Diseases of the Eye and Adnexa

• New Codes:
• Inflammations of the eyelid
• Other orbit disorders
• Neovascular secondary angle closure glaucoma

🔹 Chapter 12: Diseases of the Skin and Subcutaneous Tissue

• New Codes:
• Cutaneous abscess of the flank
• Furuncle and cellulitis of the flank
• Acute lymphangitis of the flank
• Non-pressure chronic ulcers at various sites

🔹 Chapter 19: Injury, Poisoning, and Certain Other Consequences of External Causes

• New Codes: 213 codes covering injuries of the flank, contusions, bites, lacerations, and puncture wounds

🔹 Chapter 21: Factors Influencing Health Status and Contact with Health Services

• New Codes:
• Genetic susceptibility
• Family history
• Social determinants of health, including utility insecurity

📊 Summary of ICD-10 2026 Updates

Key Highlights:

• Chapter 19: Largest updates with 213 new codes for injuries
• Chapter 12: 116 new skin and subcutaneous tissue codes
• Social Determinants of Health: New codes reflect growing importance in healthcare

💡 How Healthcare Providers Can Prepare

• Review chapter-wise updates and identify codes relevant to your specialty
• Update EHR systems with new, revised, and deleted codes
• Educate staff and coders on changes to reduce errors and claim denials
• Monitor billing and reimbursement trends for compliance

✅ Conclusion

The ICD-10 2026 updates introduce significant changes across multiple chapters, improving diagnostic specificity and documentation. Staying current ensures compliance, accurate coding, and smoother medical billing processes.

For the complete list of ICD-10 2026 updates, visit the CMS ICD-10 page.