US · guidance
CMS Pub. 100-04, ch. 13, § 40.2
Medicare Summary Notices (MSN), Reason Codes, and Remark Codes
The A/B MAC denies MRI line items on claims when billed with the appropriate MRI code and a
diagnostic code for cardiac pacemaker if modifier KX is not present.
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: 188
RARC: N/A
MSN: 21.8
The A/B MAC denies MRI line items that do not include all of the following line items:
• An appropriate MRI code,
• If ICD-9-CM is applicable, ICD-9 code V45.02 (automatic implantable cardiac defibrillator) or
ICD-9 code V45.01 (cardiac pacemaker),
• ICD-10-CM is applicable, ICD-10 code Z95.810 (automatic implantable cardiac defibrillator)or
ICD-10 code Z95.0 (cardiac pacemaker),
• Modifier Q0,
• If ICD-9-CM is applicable, ICD-9 code V70.7 Examination of participant in clinical trial (for
institutional claims only)or
• If ICD-10-CM is applicable, ICD-10 code Z00.6 – Examination of participant in clinical trial (for
institutional claims only), and
• Condition code 30 (for institutional claims only).
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: 272
RARC: N386
MSN: 21.21
History
(Rev. 3650, Issued: 11-10-16, Effective: 02-10-17, Implementation: 02-10-17)
Provenance
- Source
- cms.gov
- Retrieved
- 2026-08-25
- Edition
- iom-2026-08-25
- Content hash
2c7130f145cbecd494bafaa86d34736b02a445a245c86bf977b6de6b167ca8c5
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