CARC 257 Active

CO-257: Claim Undetermined During Premium Grace Period (HIX)

TL;DR

CO is unusual for this code — verify with the payer that it wasn't miscoded. CARC 257 should typically appear as OA since it's a temporary hold, not a final contractual adjustment.

Action
Review & Decide
Who Pays
Provider
Appeal
No
Patient Impact
None
Disclaimer
This content is for informational purposes only and does not constitute professional billing advice. Always verify information against your payer contracts and current coding guidelines. Consult a certified billing specialist for specific claim issues.

What Does CO-257 Mean?

CO-257 is uncommon and may indicate a processing anomaly. The standard pairing for CARC 257 is OA, since the grace period adjustment is a temporary hold rather than a final contractual obligation. If you receive CO-257, contact the payer to verify the Group Code assignment is correct and request reprocessing if it should have been OA.

CARC 257 appears when a claim is submitted for a patient enrolled through the Health Insurance Exchange (Marketplace) whose premium payment is overdue. Under ACA regulations, subsidized Marketplace enrollees receive a 90-day grace period before coverage can be terminated for non-payment of premiums.

During the first month of the grace period, payers must process and pay claims normally. During months two and three, however, payers may pend or deny claims with CARC 257, indicating the claim's final disposition depends on whether the patient ultimately pays the overdue premium. This is not a permanent denial — it is a temporary hold.

If the patient pays the premium, claims held under CARC 257 should be automatically reprocessed and paid. If the patient does not pay and coverage is retroactively terminated, the provider must bill the patient directly for services rendered during the retroactive termination period. The primary Group Code is OA, reflecting the temporary and informational nature of the adjustment.

How to Resolve

  1. Verify the Group Code Contact the payer to confirm whether CO is the intended Group Code. CARC 257 is designed for use with OA, and CO may indicate a processing error.
  2. Request reprocessing If the CO assignment was an error, request the payer to reprocess the claim with the correct OA Group Code.
  3. Follow standard resolution if confirmed If the payer confirms CO is correct, follow the standard resolution process — verify premium status, monitor for resolution, and take action based on the outcome.
Do Not Appeal This Code

Claim Undetermined During Premium Grace Period (HIX) recorded under CO is a contractual obligation — the provider absorbs this amount per the payer agreement. Without an error in how the contract was applied, appeals don't apply. Review the accompanying RARC codes for context and accept the adjustment when the contract terms were applied correctly.

How to Prevent CO-257

Also Filed As

The same CARC 257 may appear with different Group Codes:

OA-257 PR-257

Related Denial Codes

CO-3 — Co-payment Amount CO-85 — Patient Interest Adjustment CO-100 — Payment Made to Patient/Insured CO-101 — Predetermination: Anticipated Payment CO-105 — Tax Withholding Amount

Sources

  1. https://www.mdclarity.com/denial-code/257
  2. https://resdac.org/sites/datadocumentation.resdac.org/files/Adjustment%20Reason%20Code%20Code%20Table%20(TAF%20Claims).txt
  3. https://x12.org/codes/claim-adjustment-reason-codes
  4. Codes maintained by X12. Visit x12.org for official definitions.