CO 242 denial code

What CO-242 means

Reason code 242 means the services did not come from the providers the plan requires: its contracted network, or the primary care or designated provider the patient’s plan channels care through. In managed care designs like HMOs and EPOs, seeing the right kind of provider is a condition of payment, and this code fires when the claim fails that test.

The group code decides who absorbs it. As CO-242, the balance is a contractual obligation: the practice writes it off, often because a contracted provider’s claim did not match the network roster. The same reason appears as PR-242 when the plan puts out-of-network liability on the patient. Never assume; check each line.

Common causes

• The rendering clinician genuinely is not contracted with the plan, even though the group or facility is.
• The claim’s rendering NPI or tax ID does not match what the payer’s network file expects, so a contracted provider looks out-of-network.
• Credentialing was still in process on the date of service; the contract’s effective date came later.
• The plan requires care through a designated primary care provider or referral pathway, and the claim shows neither.
• The patient changed to a narrow-network plan and the practice, in-network for their old plan, is outside the new one.

How to fix and resubmit

1. Confirm network status for the exact date of service: the rendering NPI, the billing tax ID, and the specific plan (not just the payer brand, since one insurer runs many networks). Verify the NPIs on the claim with an NPI lookup.
2. If the provider was in network and the claim data was wrong (wrong rendering NPI, old tax ID), submit a corrected claim with the right identifiers.
3. If the claim was right but the payer’s roster is wrong, contact provider relations with the contract or credentialing confirmation, get the roster fixed, then request reprocessing or appeal with the effective-date evidence.
4. If the plan required a referral or designated-provider pathway that was actually followed, appeal with the referral documentation.
5. If the provider truly was out of network with no exception (no emergency, no authorized out-of-network approval), the CO amount is a write-off. Do not move it to the patient unless the payer reissues the line as PR.

How to prevent it

Verify network participation per plan at scheduling, especially for new patients and January plan changes. Keep a current roster of which clinicians are credentialed with which plans, and hold new hires’ claims until effective dates are confirmed. Reconcile your NPIs and tax IDs against payer directories quarterly; roster drift is constant. For plans with referral or PCP-designation rules, make the referral a booking requirement, and check the payer’s policy on out-of-network exceptions before rendering non-emergency care.

Related: CO-24 (covered under a capitation arrangement) and CO-B7 (provider not certified or eligible for the service). More at the denial codes index.