OA 257 denial code

Claim adjustment reason code 257. Often reported as OA 257.

Exchange grace period: claim pending

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 257 means

The patient is in a marketplace premium grace period, so the claim's outcome is on hold until the premium status is settled.

Members who get premium tax credits on a health insurance exchange plan have a grace period when they fall behind on premiums. After the first month of that period, a plan may hold claims rather than pay or deny them.

This code is only used with group code OA. If the premium is paid, the plan reverses and reprocesses the claim. If coverage ends, the claim is typically denied for no coverage.

Group codes seen with 257

On a remittance, 257 comes after a group code. These are the ones it is most often reported with:

• OA 257 (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 is behind on premiums for an exchange plan with premium tax credits.
• The date of service falls in the second or third month of the grace period.
• The plan pends claims instead of paying them while premiums are unpaid.

What to do next

1. Leave the balance open and note the grace period status on the account.
2. Let the patient know their coverage is at risk until premiums are brought current.
3. Watch for a reversal and corrected remittance, and check eligibility again after the grace period ends.
4. If coverage is terminated, follow your policy for self pay or other coverage once the denial arrives.

Related codes

• 277 (reason code) SHOP grace period: claim pending
• 27 (reason code) Service after coverage ended