CO 14 denial code

Claim adjustment reason code 14. Often reported as CO 14.

Patient born after the date of service

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 14 means

The date of birth the payer has is later than the date of service, which makes the claim impossible as billed.

The date of service on the claim comes before the patient's date of birth on file. This almost always means a typo in a date, a newborn billed before their record was set up correctly, or a claim filed under the wrong patient.

It is reported as a CO denial and a corrected claim usually fixes it.

Group codes seen with 14

On a remittance, 14 comes after a group code. These are the ones it is most often reported with:

• CO 14 (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

• A date of service or date of birth was keyed incorrectly.
• A newborn's claim used a placeholder date of birth that was never updated.
• The claim was attached to the wrong patient account, such as a sibling.

What to do next

1. Compare the date of service and date of birth on the claim with the medical record.
2. Update the patient's demographics and send a corrected claim.
3. For newborns, confirm the baby has been added to the policy with the correct date of birth.

Related codes

• 13 (reason code) Patient died before the date of service
• 6 (reason code) Code does not fit the patient's age
• 16 (reason code) Missing information or billing error