Claims Processing Error Code

Insurance / Claims Processing

X12 EDI Acknowledgments (AK9)

AK9-M | Group Rejected (MAC Failed)

Industry

Insurance

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/insurance/claims-processing/error-codes/ak9-m/

Last Updated

Apr 16, 2026

Summary

AK9-M means the functional group was rejected because the message authentication code (MAC) failed.

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What This Code Means

AK9 “M” is a group-level rejection condition tied to message authentication. Treat it as a security/transport issue until you confirm otherwise.

Step-by-step fix

1) Confirm certificates/keys are current and correctly configured for the trading partner endpoint.

2) Validate signing/encryption settings against the partner’s onboarding profile.

Related Codes

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