Services not authorized by network or primary care provider
The plan requires the primary care provider or the network to authorize or refer the service, and no referral or authorization is on file.
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
- HMO patient seen by a specialist without a referral from the primary care provider.
- Referral issued but expired or for a different specialist.
- Referral number not on the claim.
The fix
If a referral exists, add the referring provider and referral number and send a corrected claim. If not, ask the primary care provider for a retroactive referral (many plans allow it within a short window). Otherwise appeal with the clinical reason, or bill the patient when the plan allows and the patient was told.
Appeal or corrected claim?
Corrected claim when the referral exists; retro referral then resubmission; appeal as a last step.
Deadline to watch
Retro referral windows are short; timely filing still applies.
Exact limits are in your payer contract or provider manual. When in doubt, send the correction or appeal this week.
CO-243 in short
What does CO-243 mean?
The plan requires the primary care provider or the network to authorize or refer the service, and no referral or authorization is on file. The official X12 text reads: "Services not authorized by network/primary care providers."
What usually causes a CO-243 denial?
HMO patient seen by a specialist without a referral from the primary care provider. Referral issued but expired or for a different specialist. Referral number not on the claim.
How do I fix CO-243?
If a referral exists, add the referring provider and referral number and send a corrected claim. If not, ask the primary care provider for a retroactive referral (many plans allow it within a short window). Otherwise appeal with the clinical reason, or bill the patient when the plan allows and the patient was told.
Should I appeal CO-243 or send a corrected claim?
Correct or appeal (see note). Corrected claim when the referral exists; retro referral then resubmission; appeal as a last step.
What deadline applies to CO-243?
Retro referral windows are short; timely filing still applies.