IPPS: FY2027 MCE and ICD-10 Updates — Audit Inpatient Claims Before October 5
CMS Transmittal R13813CP updates the Medicare Code Editor and ICD-10 code sets for FY2027, with changes effective October 5, 2026.
Action required by
October 5, 2026
Review the Action Required section below and ensure your team has completed all compliance steps before this date.
CMS Transmittal R13813CP implements the FY2027 annual update to the Medicare Code Editor (MCE) and ICD-10-CM/PCS code sets, with an effective date of October 5, 2026. This is an administrative transmittal — not a Proposed or Final Rule — governing claims processing logic and diagnosis/procedure code validity for inpatient claims adjudicated under the Inpatient Prospective Payment System (IPPS). The single most critical compliance implication: any inpatient claim with a discharge date of October 1, 2026 or later must use only FY2027-valid ICD-10 codes, and the MCE will reject or return claims containing deleted or invalid codes beginning with the go-live date of October 5, 2026.
Regulatory Background
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Quick answers
Our encoder vendor says their FY2027 update won't be deployed until October 3. Is that soon enough given the October 5 FISS go-live in R13813CP?
The FISS go-live for MCE and ICD-10 FY2027 edits under R13813CP is October 5, 2026, meaning claims processed on or after that date will be validated against the new code tables. An encoder update on October 3 gives your coding team two days to code October 1–2 discharges under FY2027 logic before FISS is live — technically sufficient, but only if coders do not submit those claims before October 5 using FY2026 codes. Confirm with your vendor that the October 3 deployment covers both ICD-10-CM/PCS code tables and any MCE logic updates, and do not release October 1+ discharge claims to billing until the encoder is confirmed live.
Does R13813CP affect outpatient claims edited by the Outpatient Code Editor (OCE), or only inpatient FISS claims?
Transmittal R13813CP specifically addresses the Medicare Code Editor (MCE) and its application within FISS for inpatient claims processed under IPPS. The Outpatient Code Editor (OCE), which governs OPPS claim validation, is updated under separate transmittals. Outpatient revenue cycle and coding staff should not assume R13813CP covers their OCE edit tables — monitor CMS transmittals separately for the FY2027 OCE update.
How should we handle inpatient claims with discharge dates of October 1–4, 2026 if our billing team doesn't submit them until after October 5?
Per R13813CP, the MCE FY2027 logic activates in FISS on October 5, 2026. Any 837I claim submitted on or after that date — regardless of discharge date — will be validated against FY2027 code tables. Claims for October 1–4 discharges that are coded with deleted or revised FY2026 codes and submitted after October 5 will be returned by the MCE. Code those discharges using FY2027-valid ICD-10-CM and ICD-10-PCS codes before submission.
Content summarized from publicly available federal publications including CMS, MAC contractors, and the Federal Register. CLV Intelligence is not affiliated with or endorsed by any government agency. This is not legal or medical advice.