October 2026 Integrated Outpatient Code Editor Update

Transmittal 13979 Brings I/OCE to Version 27.3

Rcmaxis Billing & Policy Update  ·  Posted October 11, 2026  ·  Effective: October 01, 2026 (implementation October 05, 2026)

Summary of the Rule or Edit Change

The Integrated Outpatient Code Editor, I/OCE, is the software CMS and Medicare Administrative Contractors run against every institutional outpatient claim to apply OPPS-related edits before a claim is priced and paid. Transmittal 13979 (Change Request matching the October 2026 release) updates I/OCE to version 27.3, carrying the quarterly edit changes that accompany the October 2026 OPPS update, including new and revised HCPCS and CPT codes, APC assignments, and the edit logic that checks claims against them.

I/OCE sits downstream of the HIPAA front-end edits covered in our EDI update from earlier this month. A claim can pass the front-end TA1 and 999 acknowledgment checks and still be returned, rejected or have line items denied by I/OCE if it fails an OPPS-specific edit, such as an invalid code-and-modifier combination, a units-of-service limit, or a code that isn't valid for the date of service under the quarterly update.

Action Required for Billing Teams

CMS publishes the detailed edit list in the technical specifications and code lists that accompany each quarterly I/OCE release rather than in the transmittal text itself, so the practical detail sits with your practice management vendor or clearinghouse's claim-scrubbing logic. Confirm your vendor has loaded version 27.3 before claims with October dates of service go out.

Our update on October 2026's OPPS quarterly code changes covers the new PLA, Category III and drug codes that I/OCE v27.3 is built to recognize.