CO-16 — Claim lacks information / submission error
Also seen as: CO-16, PR-16
What it means
A catch-all 'something's missing or wrong' code. On its own it says nothing — the paired remark code (RARC, e.g. an N- or MA- code) tells you WHAT is missing. Always read the remark code next to it.
Standard definition (paraphrased): Something about how this claim was submitted didn't pass the payer's edits — a required piece of data was missing or something was filled out incorrectly — and a separate remark code spells out which.
Why it happens
- • A required field (NPI, taxonomy, member ID, diagnosis) is missing or invalid
- • A remark code beside it names the specific missing item
- • Common on first submissions with incomplete provider or subscriber data
Common next steps therapists take
- • Read the accompanying remark code — it names the exact missing item
- • Supply the missing information and resubmit as a corrected claim
A blank appeal-letter template is available for this kind of denial — Out-of-network claim reconsideration.
Educational information only
This page is general educational information, not legal, billing, or medical advice, and not a determination about any specific claim. Denial codes are maintained by the X12 committee and updated periodically. Always verify code meanings, benefits, and requirements directly with the payer and against your own records.
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Superbilled generates insurance-ready superbills with the correct codes and modifiers, so fewer claims come back with a code like CO-16 to decode.
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