Automatic Notice of Change to MSP Auxiliary File

30.4 - Automatic Notice of Change to MSP Auxiliary File (Rev. 12078; Issued:06-14-23; Effective: 05-29-23; Implementation: 05-29-23) The Common Working File (CWF) sends MSP transactions to all contractors of record when an MSP auxiliary record is created or changed for any beneficiary. Alerts are sent to the A/B MACs and DME MACs when an update is made to an MSP record.