CO 102 denial code

Claim adjustment reason code 102. Often reported as CO 102 or PR 102.

Adjusted under major medical benefit

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 102 means

The payment was adjusted under the patient's major medical benefit rather than the base plan benefit.

Some older plans pay services first under a basic benefit and then under a major medical layer with its own deductible, coinsurance and limits. This code shows that the major medical part of the plan changed the amount paid.

It is uncommon on modern plans. When you see it, look at the other adjustments on the line to see how much the patient owes under the major medical terms.

Group codes seen with 102

On a remittance, 102 comes after a group code. These are the ones it is most often reported with:

• CO 102 (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 102 (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 member's plan has a separate major medical benefit layer.
• The base benefit was exhausted, so the payer processed the remainder under major medical.
• Major medical deductible or coinsurance terms reduced the payment.

What to do next

1. Review the member's plan structure to see how the basic and major medical benefits interact.
2. Check the remaining adjustments on the line to see what is assigned to the patient.
3. Call the payer if it is unclear which benefit layer applied.

Related codes

• 1 (reason code) Amount applied to the deductible
• 2 (reason code) Patient's coinsurance share
• 119 (reason code) Benefit maximum reached