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CO-240 Denial Code: Diagnosis vs Birth Weight Mismatch

CO-240 means the diagnosis is inconsistent with the patient's birth weight. A newborn or neonatal claim reports a birth weight that conflicts with a weight-specific diagnosis, such as a low birth weight code that does not match the reported grams.

Quick facts

Code
CO-240 (CARC 240)
Status
Active In use since June 3, 2012; last modified July 1, 2017.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The provider is responsible for correcting the claim. The amount generally cannot be billed to the patient's family.
Official description
The diagnosis is inconsistent with the patient's birth weight. Usage: Refer to the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF), if present.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-240 means

CARC 240 says the diagnosis is inconsistent with the patient’s birth weight. It is a newborn edit. Some ICD-10-CM diagnoses describe a specific weight range, and some payment systems (such as neonatal DRGs) depend on birth weight. When the weight reported on the claim and the weight implied by a diagnosis code disagree, the claim fails this edit.

For example, a claim reports a birth weight in the normal range but carries a diagnosis for low birth weight in a much lower gram range. One of the two must be wrong, and the payer will not guess which. The official usage points to the 835 Healthcare Policy Identification REF in loop 2110, where the payer may name the edit policy.

Common causes

  • Birth weight entered in pounds or ounces instead of grams, producing an impossible value.
  • Typo in the birth weight value, such as a missing or extra digit.
  • Diagnosis selected from the wrong weight range in the low-birth-weight category.
  • Birth weight omitted, defaulting to zero or a placeholder.
  • Admission weight used instead of birth weight for a later readmission, when the payer expects birth weight.

How to fix it

  1. Pull the birth record and confirm the actual birth weight in grams.
  2. Compare it with the diagnosis codes in box 21 (professional) or the diagnosis fields on the institutional claim.
  3. Correct whichever is wrong. Update the birth weight value (for institutional claims, value code 54) or choose the diagnosis that matches the documented weight.
  4. Submit a corrected claim (frequency code 7 with the original claim number) or a new claim, following the payer’s rules.
  5. Recheck DRG assignment for inpatient claims, because a corrected weight or diagnosis can change the grouping.

How to prevent it

  • Capture birth weight in grams directly from the delivery record into the billing system.
  • Add a claim edit that compares birth weight with weight-specific diagnoses before submission.
  • Train coders to select low birth weight codes from the documented grams, not estimates.
  • Audit neonatal claims periodically for consistency between weight, gestational age, and diagnoses.

Specialty notes

This code is mostly seen by hospitals billing newborn and NICU stays and by neonatology groups. Pediatric practices billing routine newborn visits may see it if they include weight-specific diagnoses that do not match the reported weight.

Remark codes that may appear with CO-240

  • M49 (Missing/incomplete/invalid value code(s) or amount(s).): A value code or amount is missing or invalid; birth weight is often reported as a value code on institutional claims.
  • N56 (Procedure code billed is not correct/valid for the services billed or the date of service billed.): The procedure code is not valid for the services or date of service billed.
  • CO-9 (The diagnosis is inconsistent with the patient's age.): The diagnosis is inconsistent with the patient's age.
  • CO-10 (The diagnosis is inconsistent with the patient's gender.): The diagnosis is inconsistent with the patient's sex.
  • CO-11 (The diagnosis is inconsistent with the procedure.): The diagnosis is inconsistent with the procedure.
  • CO-A8 (Ungroupable DRG.): The claim could not be grouped to a DRG, which can follow from inconsistent newborn data.

CO-240 FAQ

Where is birth weight reported on a claim?

On institutional claims, birth weight is typically reported with value code 54 and the weight in grams. Professional claims may carry it in supplemental fields depending on the payer.

Which diagnoses are tied to birth weight?

ICD-10-CM has codes for low birth weight and extreme immaturity that specify weight ranges in grams, for example the P07 category. If the reported weight falls outside the range in the code, the claim can hit CO-240.

Is CO-240 an appeal or a corrected claim?

Usually a corrected claim. Fix the birth weight or the diagnosis so they agree with the medical record, then resubmit.