MSP CWF Process

30.4 – MSP CWF Process (Rev. 11755, Issued:12-21-22, Effective: 01-23-23, Implementation: 01-23-23) The CWF holds all Medicare beneficiaries’ Part A and Part B data. All beneficiaries have a master record in CWF. CMS uses the MSP Auxiliary file within CMS to identify MSP occurrences in order to ensure accurate Coordination of Benefits. Currently in Chapter 6 of the Medicare Secondary Payer Manual, the CWF process as it pertains to MSP and Coordination of Benefits is explained. It gives A/B MACs and DME MACs an idea of how to use the CWF when their role requires it and how it is used by CMS for MSP activities.