Denial codes, decoded for BH and SUD.
The thirteen claim adjustment reason codes behavioral health and SUD programs see most, with the typical BH trigger, the prevention step, and the fix for each.
A denial on an 835 tells you what happened in two characters and a number. It does not tell you that the group session was billed without the supervising clinician's NPI, or that the authorization lapsed two days before the last billed day of residential care. This cheat sheet connects each common code to the behavioral health and substance use disorder situations that usually cause it.
Every code gets three short answers: why BH and SUD claims get it, how to prevent it before submission, and what to do when it arrives anyway. The codes are grouped the way the work is: denials decided before the claim goes out, denials a pre-submission scrub should catch, and the medical necessity denials that are hardest to win back.
What is inside
- How to read a denial: group codes CO, PR, OA, and PI, and how they pair with reason and remark codes
- 13 reason codes with the typical BH and SUD trigger, a prevention step, and the next step when it arrives
- Authorization, timely filing, and duplicate claim denials grouped as front-end work
- Medical necessity and upheld appeals, with escalation steps including parity
13 codes, grouped the way the work is.
Before the claim goes out
- CO-197Precertification, notification, or authorization absent
- PR-204Service not covered under the patient's current benefit plan
- CO-96Non-covered charge
- CO-29Time limit for filing has expired
- CO-18Exact duplicate claim or service
Building the claim
- CO-16Claim lacks information or has a submission or billing error
- CO-4Procedure code inconsistent with the modifier, or a required modifier is missing
- CO-11Diagnosis inconsistent with the procedure
- CO-97Payment is included in another service already adjudicated
- CO-151Information does not support this many services or this frequency
- CO-167Diagnosis is not covered
Medical necessity and appeals
- CO-50Not deemed a medical necessity by the payer
- CO-193Original payment decision is being maintained
Built for the people who work the denials.
- Billing and RCM teams at residential, PHP, IOP, and outpatient programs
- Utilization review and admissions staff who own authorizations
- Compliance and clinical leaders who want fewer denials traced to documentation
Related on this site: Denial Fightback, Documentation Compliance, Prior Auth Autopilot.
Download the PDFCatch these before the claim goes out.
Adentris reviews charts and claims against payer rules before submission, so missing documentation, modifiers, and authorizations surface while they can still be fixed.