US · guidance

CMS Pub. 100-05, ch. 6, § 40.1

CWF, MSP Claim Validation

activein force · 2026-08-25 – presentas-observed

There are four conditions that may occur when an A/B MAC and DME MAC validates

claims against the CWF, MSP auxiliary file:

• MSP is indicated on the claim and there is matching data on the CWF, MSP

auxiliary record. The claim is accepted and all CWF, MSP auxiliary occurrences

are returned,

• MSP is indicated on the claim and there is no matching data on an MSP auxiliary

record. The claim is rejected and all CWF, MSP occurrences that apply are

returned. Section 40.8 describes the CWF, MSP Utilization Error Codes, and the

appropriate resolution for those codes,

• MSP is not indicated on the claim and the MSP auxiliary file has an occurrence

that indicates there is MSP involvement for the time period affected. The claim is

rejected and all occurrences that apply are returned, and

• MSP is not indicated on the claim and there are no matching occurrences on the

CWF, MSP auxiliary file that indicate MSP involvement. The claim is accepted

for payment.

NOTE: An occurrence applies if the claim service dates are equal to, or greater than, the

effective date of the occurrence and less than, or equal to, the termination date of that

occurrence, if there is a termination date.

History

(Rev. 12078; Issued:06-14-23; Effective: 05-29-23; Implementation: 05-29-23)

Provenance

Source: cms.gov
Retrieved: 2026-08-25
Edition: iom-2026-08-25
Content hash: bfae33692290a6bd5da2fc3b808b4859c6a2f8f34ecb41c3dac32246025e7bfe

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