CO-306 Denial Code: Bill Type Conflicts With Patient Status

What CO-306 means

CARC 306 says the type of bill is inconsistent with the patient status. On an institutional claim (UB-04 or 837I), the type of bill in form locator 4 describes the facility type, care type, and claim frequency, such as an admit-through-discharge bill, an interim bill, or a replacement. The patient discharge status in form locator 17 tells the payer where the patient went at the end of the billing period, or that they’re still a patient. When these two fields contradict each other, the payer can’t price the claim correctly and denies it with CO-306.

The usage note points to the 835 Healthcare Policy Identification segment for any policy the payer applied.

Example: a hospital submits an interim bill for the first part of a long stay (type of bill ending in 2) but the patient status shows 01, discharged home. The payer can’t tell whether the stay is complete, so it denies the claim.

Common causes

• Interim bills with a discharge status instead of 30 (still a patient).
• Final or admit-through-discharge bills showing status 30.
• Discharge status updated late, after the claim was generated from an earlier interim record.
• Transfer status codes used on claims whose type of bill doesn’t allow them.
• Replacement claims that changed the frequency code without updating the status, or the reverse.
• Outpatient bill types with inpatient-only status codes.

How to fix it

1. Confirm the actual discharge disposition from the medical record and case management notes.
2. Choose the correct type of bill frequency for the billing period: admit through discharge, interim first, continuing, or last claim.
3. Align the patient status with that frequency and the real disposition.
4. Submit a corrected institutional claim using the payer’s replacement process.
5. Check for downstream effects, since discharge status can affect transfer payment rules and post-acute payments.

How to prevent it

• Build edits that block interim bill types without status 30 and final bills with status 30.
• Pull discharge status from the final discharge record, not from the admission or interim record.
• Train coders on transfer and post-acute status codes, which affect payment.
• Scrub institutional claims before release. A Claims Validator can flag type of bill and status conflicts.

Specialty notes

Hospitals, skilled nursing facilities, inpatient rehabilitation, and psychiatric facilities that bill long stays in interim periods see this code most often.