CO 143 denial code

Claim adjustment reason code 143. Often reported as CO 143 or OA 143.

Part of the payment is deferred

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 143 means

The payer is holding back part of the payment to release later rather than denying it.

The payer has decided to pay the claim, but some of the money will come at a later time. This can happen under certain contracts, settlement arrangements or payment programs where part of the amount is held until a later date or reconciliation.

It is not a denial. Keep track of the deferred amount so it can be matched when the later payment arrives.

Group codes seen with 143

On a remittance, 143 comes after a group code. These are the ones it is most often reported with:

• CO 143 (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.
• OA 143 (Other Adjustment): Used for adjustments that are neither the provider's contractual write-off nor the patient's share. It often appears with coordination of benefits, for example when another payer already paid.

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

• Your contract or a payment program releases part of the payment at a later reconciliation.
• The payer is spreading payment over time under a settlement or arrangement.
• A withhold is applied that may be returned depending on later results.

What to do next

1. Record the deferred amount separately so it is not posted as a write-off.
2. Check your contract for when and how deferred amounts are paid.
3. Follow up with the payer if the deferred amount does not arrive when expected.

Related codes

• 144 (reason code) Incentive adjustment
• 161 (reason code) Bonus for meeting performance goals