RARC MA120: Missing or Invalid CLIA Certification Number

What Does RARC MA120 Mean?

MA120 indicates that the payer rejected the claim because the Clinical Laboratory Improvement Amendments (CLIA) certification number is either absent from the claim, incomplete, or does not match a valid CLIA certificate on file. Federal law requires that all laboratory testing on human specimens (with limited exceptions for waived tests) be performed by a CLIA-certified laboratory, and payers — particularly Medicare — verify this certification as part of claim adjudication.

The CLIA number is a unique identifier assigned to each laboratory location by CMS. When a claim for a lab service is submitted without this number, or with one that does not match the CMS CLIA database, the payer cannot confirm that the laboratory meets federal quality standards. This results in an automatic denial regardless of whether the lab is actually certified.

Common causes of MA120 include data entry errors when setting up the CLIA number in the billing system, using an expired or revoked CLIA certificate number, submitting a CLIA number that belongs to a different laboratory location, or billing lab services under a provider who does not have CLIA certification for the test complexity level performed. If the laboratory recently renewed its certificate, there may be a lag between renewal and database updates that can also trigger this code.

What to Do

Look up the performing laboratory's current CLIA certificate number in the CMS CLIA database to confirm it is active and valid. Cross-reference this number against what is entered on the claim and in your billing system. If there is a mismatch, correct the CLIA number and resubmit the claim. Make sure the CLIA number corresponds to the specific lab location where the test was performed, not a corporate or reference lab location unless that is where the analysis actually occurred.

If your CLIA certificate recently expired or was renewed, contact your State Survey Agency or CMS regional office to confirm the renewal has been processed and the database updated. For practices that perform waived tests under a Certificate of Waiver, verify that the tests billed fall within the scope of that waiver — billing for moderate or high complexity tests under a waiver-level CLIA certificate will also trigger this denial.

Common Scenarios

• A physician office lab bills for a blood glucose test but the CLIA number field was left blank when the practice's billing system was set up
• A laboratory renews its CLIA certificate, but the new number has not been updated in the billing software, so claims continue to go out with the old expired number
• A multi-site practice submits lab claims with the CLIA number from its main office, but the tests were performed at a satellite location with its own separate CLIA certification

Commonly Paired With

RARC MA120 commonly appears alongside these CARC denial codes: