CO 283 denial code

Claim adjustment reason code 283. Often reported as CO 283.

Attending provider cannot direct care

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 283 means

The provider listed as attending is not eligible to direct the patient's care for this service, so the claim was not paid as billed.

Some services require that a certain kind of provider direct the care, such as a physician or a provider type the plan approves. This code says the attending provider on the claim does not qualify.

It may be a credentialing gap or simply the wrong provider entered in the attending field.

Group codes seen with 283

On a remittance, 283 comes after a group code. These are the ones it is most often reported with:

• CO 283 (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.

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 attending provider's specialty or license type does not qualify to direct that care.
• The attending provider is not enrolled or credentialed with the payer.
• The wrong provider was entered in the attending provider field.

What to do next

1. Confirm who directed the care and whether they qualify under the payer's rules.
2. Correct the attending provider on the claim if it was entered wrong.
3. Check enrollment and credentialing for the attending provider with the payer.

Related codes

• 16 (reason code) Missing information or billing error
• 299 (reason code) Billing provider cannot be paid for this