CO 253 denial code

Claim adjustment reason code 253. Often reported as CO 253.

Sequestration reduction

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 253 means

The payment was cut by a small percentage under federal sequestration, a mandated reduction to certain federal program payments.

Sequestration is a budget control that trims federal health program payments, most familiar on Medicare claims and on plans paid under Medicare rules. It is applied after the allowed amount and cost sharing are figured, so it lowers what the payer sends you, not what the patient owes.

The amount is set by law rather than by a coding or billing error, so there is usually nothing to fix. It typically shows with group code CO, meaning the provider absorbs it.

Group codes seen with 253

On a remittance, 253 comes after a group code. These are the ones it is most often reported with:

• CO 253 (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 claim was paid by Medicare or a plan whose payments follow Medicare sequestration rules.
• The reduction applies to the paid amount on every claim from that payer, not to a specific service.
• A contract with a Medicare Advantage or other plan passes the federal reduction through to providers.

What to do next

1. Confirm the reduction is a small percentage of the payment rather than a larger, unexplained cut.
2. Post it as a contractual adjustment according to your posting rules, keeping it separate from fee schedule adjustments for reporting.
3. Do not transfer the amount to the patient, since it does not change patient cost sharing.
4. If a commercial plan applies it, check your contract to see whether it allows the payer to pass the reduction through.

Related codes

• 45 (reason code) Charge exceeds the allowed amount