Navigating the 2026 ICD-10-CM coding updates

The annual ICD-10-CM code set update, effective October 1, features new codes, revised guidelines, and editorial adjustments that require careful analysis and strategic implementation. Navigating the complexities of these coding changes is crucial for healthcare organizations aiming to optimize their risk adjustment programs. This also provides an excellent opportunity for collaboration and partnership.

Early preparation, collaboration, and continuous education for coding teams are all critical to reducing learning curves and ensuring accurate coding. Health plans need to be ready to review the latest ICD-10-CM updates and to adopt best practices to prepare, adjust, and thrive in the new year.

Breaking down the 2026 coding updates

Coding teams must be trained on current updates and potential mappings to help them become acclimated to the changes. Here is an overview of some key changes and examples:

• 480 new ICD-10-CM codes in various categories
• More than 140 new codes with potential mapping in Medicare and commercial risk adjustment programs
• Examples of new codes that we are monitoring and training for include:
  • C50.A: Malignant inflammatory neoplasm of the breast
  • E11.A: Type 2 diabetes mellitus without complications, in remission

C50.A falls in line with a general increased focus on documentation accuracy for cancer conditions to avoid common coding errors, as highlighted in the OIG Toolkit for Medicare Advantage organizations. This includes consistency with clinical evidence and use of “history of” data.

For E11.A, diabetes is always a condition with higher complexity, and the remission code for this condition is brand new. Training should include examples of provider documentation and code assignment guidelines. The E11.A code is assigned based on provider documentation that the diabetes is in remission, so the provider must document “in remission” for the code to be used. If questions remain, coders should check guidelines for references on applicable terminology and documentation.

In addition to the annual coding updates revision, the transition to Model V28 will be complete in 2026. Plans should view this as a strategic and comprehensive change rather than just an update. Some of the most notable details include:

• Significant HCC numbering changes: Only three HCCs have kept the same title and number​ in the ICD-10-CM code set versus the ICD-9-CM code set​.
• Substantial diagnosis code changes: ICD-10-CM is more granular (74,000 + codes) than ICD-9-CM (14,000 + codes), leading to greater specificity in the modeling results. 525 have the word “unspecified” in the title, meaning that they require further details in documentation and exactness in their coding.

One example of enhanced exactness and specificity is metastatic cancer. ICD-10-CM’s coding updates for metastatic cancer focus on more detailed coding and on identifying both primary and secondary tumors (Figure 1).

V24

Best practices for implementation

Plans should always consider early preparation and continuous education for coding teams to make a significant difference in applying coding updates, and ICD-10-CM is no different. Organizations should assess training opportunities, anticipate the impact of HCC model changes, and monitor trends year over year. Check for updates, import them into applications and test, making sure that they have been integrated seamlessly, then educate coding teams. Plans should also look to refine natural language processing (NLP), which improves with continuous and meaningful feedback, and enlist the coding team for support.

Effective ICD-10-CM implementation requires collaboration across coding, training, compliance, and data analytics teams. Here are some ideas to implement along the way:

• Leverage official industry resources (e.g., CMS memos, newsletters) and encourage coders to stay informed beyond internal materials.
• Maintain alignment and strategy among all stakeholders at the start of each risk season, ensuring close collaboration between internal teams and external partners.
• Establish strong frameworks for continuous oversight, leveraging technology (NLP, AI) while maintaining human oversight and feedback loops.
• Adapt coding programs to incorporate more prospective and concurrent models, enabling more timely risk mitigation and provider education.

Foster partnerships and open communication to share insights and adapt to changes. Regular training, clear communication, and a balance between technology and human expertise are key to maintaining high coding standards and compliance.