Denial codes / CO-29

Denial code 29

CO-29: Filing deadline passed

Time limit for filing has expired.

What to doAppeal with evidence
Often recoverableUsually not

The letters in front matter. CO means the office can't bill the patient for the amount; PR means the patient may owe it. The same number can appear with either, so read both parts.

Why dental offices see it

  • The claim was sent after the insurer's filing limit.
  • The original claim was rejected by the clearinghouse and nobody noticed.
  • A secondary claim waited too long for the primary EOB.

What to do

  1. Find proof the claim was first sent on time: the clearinghouse acceptance report or insurer acknowledgment.
  2. Appeal with that proof.
  3. Without proof, the amount is usually written off; do not bill the patient for a contracted plan.

Stop it next time

Track every claim's filing deadline from the date of service, and review clearinghouse rejections daily. Filing limits vary by insurer and contract; check yours.

How many CO-29 claims are in your report? The free check counts them, ranks them by dollars and deadline and drafts the letter. It runs in your browser; nothing is uploaded.

Run the free check

Plain-English paraphrase; the official code list is maintained by X12. Insurer rules vary; check the insurer's provider manual. Not legal advice.