Missing Information / Unprocessable Claims
CARC 16The payer returned the claim unprocessed because required data was missing.
What it is
The pattern
A missing-information denial (often CARC 16) means the claim could not be adjudicated at all — it was returned unprocessed until the missing data arrives. This is not a coverage decision; it is a request for more information.
Why it happens
Common causes
- Required fields (modifiers, NPI, taxonomy, referring provider) were absent or invalid.
- The claim was submitted with an incomplete or conflicting diagnosis.
- Attachments were referenced but never attached.
- The clearinghouse edit passed, but the payer's front-end edit did not.
Prevention
Stop it before the claim goes out
- Run clean-claim edits at the practice level, not just at the clearinghouse.
- Use the payer's claim-scrubber or pre-adjudication tools before submission.
- Standardize the intake checklist so referring-provider and modifier fields are never blank.
When it happens
What to do
Correct the flagged field and resubmit promptly — the claim number and DOS stay the same. Watch the payer's resubmission window; many count the original filing date for timely-filing purposes.
Deeper dive
The full denial guide
The claim was missing required information or had a submission or billing error, so the payer could not process it. This is usually a correction, not an appeal.
Open the Missing Information guide →