CARC 16 denial: what it means and how to fix it
What it means
CARC 16 means the payer couldn't process the claim because required information is missing or a submission/billing error was found. It's one of the most common denials — and usually one of the most fixable: correct the missing or invalid element and resubmit.
Common causes
- A required field was blank, missing, or invalid on the claim.
- A diagnosis, procedure code, modifier, or identifier didn't meet the payer's requirements.
- A referring/ordering provider identifier was missing when the service required one (often paired with a RARC naming the exact field).
How to fix it
- Read the accompanying RARC(s) on the remittance — they pinpoint the missing or invalid element.
- Correct the specific field on the claim (or attach the required information).
- Resubmit, or send a corrected claim if the original was already adjudicated.
Appeal / resubmit
CARC 16 is usually resolved by correcting and resubmitting rather than a formal appeal. If the information was present and valid, resubmit with documentation showing it.
Frequently asked
Is CARC 16 an appealable denial?
Most CARC 16 denials are fixable by correcting the claim and resubmitting, so a formal appeal is often unnecessary.
How do I know which field is missing?
Check the RARC codes returned alongside CARC 16 — they identify the specific missing or invalid element.
More free billing tools: all denial codes · denial lookup · Medicare fee calculator
Informational only — not billing or legal advice.
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