US · guidance
CMS Pub. 100-04, ch. 17, § 100.5.1
Denials Due to Medical Necessity
If the lines are not approved due to medical necessity, the contractor shall use the
following remittance advice messages and associated codes when rejecting/denying
claims under this policy. This CARC/RARC combination is compliant with CAQH
CORE Business Scenario Three.
Group Code: CO
CARC: 50
RARC: N661
MSN: 16.48
History
(Rev. 3721, Issued: 02-24-17, Effective: 05-25-17, Implementation: 05-25-17)
Provenance
- Source
- cms.gov
- Retrieved
- 2026-08-25
- Edition
- iom-2026-08-25
- Content hash
1933c9d0f2d2813d1ef76e91e70d233a91d4e34a7ca44e4709c687fa26d181a4
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