The California Department of Health Care Services (DHCS) is consulting with stakeholders to obtain feedback regarding an upcoming policy change that will require ICD-10 diagnosis codes to be included on all Medi-Cal Rx pharmacy claims.

This message serves as both a reminder and an early notice:

• Reminder: If not already doing so, prescribers and pharmacy providers are encouraged to begin including clinically appropriate ICD-10 diagnosis codes on all pharmacy claims.
• Notice: Beginning in mid-2026, ICD-10 diagnosis codes will become a required field on all Medi-Cal Rx pharmacy claims. Additional details regarding the implementation timeline will be shared following the conclusion of this stakeholder engagement and through standard communication channels.

To prepare for this upcoming change, DHCS strongly encourages prescribers and pharmacy providers to begin including ICD-10 diagnosis codes on pharmacy claims immediately. This aligns with:

• Current Medi-Cal requirements for medical claims,
• Best practices in clinical documentation,
• Aligns with guidance from the American Pharmacists Association (APhA), which supports the use of diagnosis codes in pharmacy practice.

Why This Matters:
ICD-10 diagnosis codes, when submitted with pharmacy claims, enable DHCS to:

• Monitor utilization trends,
• Identify opportunities for policy improvements,
• Implement appropriate utilization management controls (e.g., prior authorization),
• Reduce administrative burden on providers,
• Improve timely access to care for Medi-Cal members,
• Promote clinical appropriateness, efficacy, safety, and quality of care.

Some pharmacy point-of-sale (POS) systems may automatically populate ICD-10 codes from electronic prescriptions. As a best practice, pharmacy providers should document the diagnosis and ICD-10 code on the prescription or in the member’s electronic record for auditing purposes.

Currently, ICD-10 diagnosis codes are required for a subset of medications listed on the Medi-Cal Rx Contract Drug List (CDL). Claims for drugs with Code 1 ICD-10 requirements will be denied if the appropriate code is not included. For more information, please refer to the Medi-Cal Rx CDL and Covered Products List.

DHCS welcomes your feedback and looks forward to working collaboratively to ensure a smooth transition and requests that comments or feedback be emailed to medi-cal.pharmacybenefits@dhcs.ca.gov no later than November 21, 2025, by close of business.