Patient cannot be identified as insured
The payer could not find this patient in its membership file using the ID, name and date of birth on the claim.
CO = Contractual Obligation. The provider owes the difference. The patient cannot be billed for this amount. The same reason code can appear with a different group code; the group decides who may be billed.
Usual causes
- Member ID typed wrong or missing a prefix or suffix.
- Name or date of birth does not match the card (nicknames, hyphenated names, transposed digits).
- The patient is covered under a spouse or parent and the subscriber information is missing.
- Claim sent to the wrong payer with a similar name.
The fix
Compare the claim to a copy of the card and the eligibility response. Correct the ID, name, date of birth or subscriber fields and send a corrected claim. If the patient is not actually covered, bill the patient or the right payer.
Appeal or corrected claim?
Corrected claim.
Deadline to watch
Timely filing limit from the date of service.
Exact limits are in your payer contract or provider manual. When in doubt, send the correction or appeal this week.
CO-31 in short
What does CO-31 mean?
The payer could not find this patient in its membership file using the ID, name and date of birth on the claim. The official X12 text reads: "Patient cannot be identified as our insured."
What usually causes a CO-31 denial?
Member ID typed wrong or missing a prefix or suffix. Name or date of birth does not match the card (nicknames, hyphenated names, transposed digits). The patient is covered under a spouse or parent and the subscriber information is missing. Claim sent to the wrong payer with a similar name.
How do I fix CO-31?
Compare the claim to a copy of the card and the eligibility response. Correct the ID, name, date of birth or subscriber fields and send a corrected claim. If the patient is not actually covered, bill the patient or the right payer.
Should I appeal CO-31 or send a corrected claim?
Corrected claim. Corrected claim.
What deadline applies to CO-31?
Timely filing limit from the date of service.