2025 Mid-Year CMS-HCC Update: What Medical Coders Need to Know

2025 Mid-Year CMS-HCC Update: What Medical Coders Need to Know

The Centers for Medicare and Medicaid Services (CMS) has released its mid-year update to the Hierarchical Condition Category (HCC) mappings and weights for 2025. The 2025 HCC updates represent an important development for medical coders, healthcare providers, and revenue cycle management professionals. The primary change in this release involves the addition of new diagnosis codes to existing HCC categories for CMS v28, while maintaining stability in other aspects of the HCC model.

Refer to our articles, “Upcoming Changes to 2024 CMS-HCC Risk Adjustment Model Include Reliable Predictors of Future Costs” and “2024 HCC Changes: Understanding the Impact on Healthcare Providers and Medical Coders,” for more information about the previous HCC update.

Key Highlights of the Mid-Year Update

• No changes to CNA weights: The Community Non-dual Aged weights remain unchanged from the previous release.
• No HCC categories deleted or modified: All existing HCC categories continue to function as before.
• No diagnoses removed or reassigned: No existing diagnosis codes were removed from HCC categories or had their HCC category assignments changed.
• Addition of new diagnosis codes: Several new ICD-10-CM codes have been mapped to existing HCC categories – no new HCC categories were created.

Analysis of Newly Added Diagnosis Codes

Our analysis of the newly added diagnosis codes reveals several important trends that medical coders should be aware of. It’s important to note that all these new codes have been mapped to existing HCC categories. CMS did not create any new HCC categories in this update.

Let’s break down these additions by category:

1. Lymphoma and Malignant Immunoproliferative Diseases

The largest group of newly added codes relates to various types of lymphoma and malignant immunoproliferative diseases. These codes primarily map to four HCC categories:

• HCC 17: Includes Sezary disease in remission and carcinoid syndrome
• HCC 19: Includes specific T-cell lymphomas such as angioimmunoblastic T-cell lymphoma and blastic NK-cell lymphoma
• HCC 20: Includes multiple lymphoma types such as mantle cell lymphoma and primary central nervous system lymphoma
• HCC 21: Includes numerous lymphoma types in remission, predominantly B-cell lymphomas

The extensive additions in this area suggest CMS is refining risk adjustment for patients with these conditions, which often require complex and costly care.

2. Rare Genetic Disorders

A small but significant addition includes:

• HCC 109: Fanconi anemia (D6103)

This rare genetic disorder causes bone marrow failure and is associated with high treatment costs and increased risk of developing certain cancers.

3. Metabolic and Nutritional Disorders

New codes in this category include:

• HCC 48: Severe obesity (E66813: Obesity, class 3) and pediatric BMI ≥ 140% of the 95th percentile (Z6856)
• HCC 153: Multiple codes for anorexia nervosa and bulimia nervosa with various severity levels

These additions reflect growing recognition of the significant health impacts and healthcare costs associated with both severe obesity and eating disorders.

4. Neurological Conditions

Several new neurological condition codes were added:

• HCC 201: KCNQ2-related epilepsy with various modifiers and developmental and epileptic encephalopathy (G40841, G40842, G40843, G40844, and G9345)

These are specific neurological conditions that typically require specialized care and management.

5. Cardiovascular Conditions

New additions include:

• HCC 267: Cement and fat embolism of the pulmonary artery, both with and without acute cor pulmonale (I2603, I2604, I2695, and I2696)

These codes address complications that can occur during medical procedures, particularly orthopedic surgeries.

6. Poisoning/Toxicity

A single new code was added:

• HCC 155: Poisoning by immune checkpoint inhibitors and immunostimulant drugs, intentional self-harm

This reflects the increasing use of immune checkpoint inhibitors in cancer treatment and the potential for adverse events.

Implications for Medical Coders and Healthcare Organizations

These additions to HCC mapping have several important implications:

1. Documentation Precision: The addition of many remission status codes for lymphomas emphasizes the importance of documenting disease status accurately.
2. Continued Coding Specificity: Many of the new codes represent highly specific conditions or variants, reinforcing the need for coders to continue their careful attention to clinical documentation details.
3. Risk Adjustment Impact and Reimbursement Opportunities: Healthcare organizations should review their patient populations for these newly added conditions, as they may now contribute to risk adjustment calculations and create new reimbursement opportunities by mapping to existing HCC categories.
4. Population Health Management: The inclusion of severe obesity and eating disorder codes reflects CMS’s recognition of these conditions’ impact on overall health outcomes and costs.

2025 HCC Updates Education: A Strategic Priority

Ensuring your coding team stays current with these HCC mapping updates is vital for organizational success. Leadership should prioritize ongoing HCC education to maximize appropriate reimbursement and support quality patient care. YES HIM Consulting provides HCC and Risk Adjustment Basics training for coding teams that need additional guidance.

For more information or specific guidance on implementing these changes, please contact our coding specialists.