CO 258 denial code

Claim adjustment reason code 258. Often reported as CO 258 or OA 258.

Patient in custody or incarcerated

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 258 means

The plan does not cover the service because the patient was incarcerated or in custody on the date of service.

Most health plans exclude care given while a person is held by a government authority, because a correctional or other public agency usually carries that responsibility. The payer may suggest that another federal, state, or local body could pay.

If the patient was not actually in custody on that date, the plan's records are wrong and can be corrected.

Group codes seen with 258

On a remittance, 258 comes after a group code. These are the ones it is most often reported with:

• CO 258 (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 258 (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

• The patient was in jail, prison, or another form of custody on the date of service.
• The plan received an incarceration notice that overlaps the date of service.
• Incarceration data is out of date and the patient had already been released.

What to do next

1. Confirm with the patient or facility whether they were in custody on the date of service.
2. If they were, bill the responsible correctional or government agency under its process.
3. If they were not, ask the plan to correct its records and then reprocess the claim, with release paperwork if available.

Related codes

• 27 (reason code) Service after coverage ended
• 109 (reason code) Not covered by this payer, send elsewhere