AKI & ESRD Billing: Ending the AX Modifier Requirement

Related CR Release Date: January 28, 2026 
MLN Matters Number: MM14354
Effective Date: July 1, 2026 
Related Change Request (CR) Number: CR 14354
Implementation Date: July 6, 2026 
Related CR Transmittal Number: R13588CP

CR 14354 tells you about:

  • ESRD facilities don’t need to submit the AX modifier on claims eligible for certain add-on payment adjustments under the ESRD PPS
  • ESRD facilities must adhere to new billing instructions for hemodiafiltration and Acute Kidney Injury (AKI) claims

Make sure your billing staff knows about these updates, starting July 1, 2026, to billing instructions for ESRD Prospective Payment System (PPS) claims and to the Medicare Claims Processing Manual, Chapter 8, sections 20, 40, and 50.

View the complete CMS Medicare Learning Network (MLN) Matters (MM)14354.

Last Updated Feb 05 , 2026