Claim adjustment reason code
Denial code CO-128 meaning
CARC 128, usually seen as CO-128: The newborn's services are included in the payment for the mother's stay.
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- Reason code
- CARC 128
- Short name
- Newborn covered in the mother's payment
- Plain meaning
- The newborn's services are included in the payment for the mother's stay.
- Group codes
- CO-128: Contractual obligation. The provider absorbs the amount under its contract or the payer's rules. Do not bill the patient for it.
Plain-English summary written by Rivvi. X12 owns the CARC list and its exact wording, which is not reproduced here. Read it on the X12 CARC list (list dated November 1, 2025, checked October 23, 2026). This page does not decide how a claim is paid.
Common causes
- The newborn care was billed separately when the payer pays it with the mother's claim.
What to check before resubmitting
- Check the payer's newborn billing rules.
Related reason codes
Related pages
Questions
What does denial code CO-128 mean?
The newborn's services are included in the payment for the mother's stay. This is Rivvi's plain-English summary of CARC 128. X12's exact wording is on x12.org.
How do I fix CO-128?
Check the payer's newborn billing rules.
Can I bill the patient for CO-128?
With group code CO, no. CO means the provider absorbs the amount under its contract or the payer's rules.
Which group codes come with CARC 128?
Most often CO (contractual obligation). The group code, not the reason code, says who owes the amount.
What is the difference between a CARC and a RARC?
A claim adjustment reason code (CARC) says why a claim line was paid differently than billed. A remittance advice remark code (RARC) adds detail, such as which field is missing.