CO 96 denial code

Claim adjustment reason code 96. Often reported as CO 96 or PR 96.

Service not covered by the plan

Unofficial reference. This is our own plain-English explanation, not the official code text. Payer rules differ. Verify with the payer and the official X12 code list. AlphaPrefix is not affiliated with X12, CMS or any payer. Data last updated Nov 11, 2026.

What 96 means

The payer does not cover this service under the patient's plan or for the way it was billed, so it was not paid.

The payer is saying this charge falls outside what it pays for. The reason can be a plan exclusion, a service that is never covered, or coverage rules that the claim did not meet. The code alone does not say which.

It must come with at least one remark code, and that remark is where the real reason lives. Check also for a policy reference at the service line. With CO, the provider usually carries the amount unless the patient signed a valid waiver or notice; with PR, the plan treats it as the patient's cost.

Group codes seen with 96

On a remittance, 96 comes after a group code. These are the ones it is most often reported with:

• CO 96 (Contractual Obligation): The provider's side of the ledger. The reduction comes from the payer contract or a rule the provider has to follow, and the patient normally cannot be billed for it.
• PR 96 (Patient Responsibility): The amount is assigned to the patient. Deductibles, coinsurance and copays are the everyday examples. Whether you can collect it still depends on your contract and the patient's plan.

The payer chooses the group code for each adjustment, so the same reason code can appear with another group code on your remittance. Read the two together. More about group codes.

Common causes

• The service is excluded under the member's benefit plan, such as cosmetic or experimental care.
• The diagnosis on the claim does not meet the payer's coverage policy for the procedure.
• The service was billed with a code, modifier or place of service the payer does not cover.
• No valid advance notice or waiver was on file for a service the provider knew might not be covered.
• The patient's coverage did not include this benefit on the date of service.

What to do next

1. Read every remark code on the line, since the remark explains why the charge was not covered.
2. Check the member's benefits and the payer's coverage policy for the procedure and diagnosis on that date.
3. Correct and resubmit if a coding, modifier or diagnosis error caused the denial.
4. Look for a signed waiver or advance notice before treating any amount as the patient's responsibility.
5. Appeal with medical records and the policy criteria if the service met coverage rules.

Related codes

• 50 (reason code) Not medically necessary per the payer
• 204 (reason code) Not covered under the patient's plan
• N130 (remark code) Check plan benefits for restrictions
• 16 (reason code) Missing information or billing error