Denial codes / CO-27

Denial code 27

CO-27: After coverage ended

Expenses incurred after coverage ended.

What to doCheck coverage, then resend
Often recoverableYes, when worked

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 patient's coverage ended (job change, plan change, lost Medicaid eligibility).
  • The insurer has the wrong termination date.

What to do

  1. Verify the termination date.
  2. Ask the patient for new coverage and bill the new plan.
  3. If coverage was active, appeal with the eligibility printout from the date of service.

Stop it next time

Check eligibility before treatment and on the day of service for long treatment plans.

How many CO-27 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.