Behavioral health practices often see higher denial rates than other outpatient specialties because of authorizations, time-based codes and telehealth rules. The good news is that most denials follow a few patterns, and each pattern has a fix.
Common denial codes and fixes
| Code | What it usually means | Prevention |
|---|---|---|
| CO-197 / CO-15 | Precertification or authorization missing or invalid | Track authorizations with visit-count and expiry alerts. Request re-authorization early. |
| CO-27 | Coverage terminated before the date of service | Re-verify eligibility at intake, at plan-year changes and monthly for Medicaid plans. |
| CO-50 | Not deemed medically necessary | Diagnosis, treatment plan and session note must support the service and its frequency. |
| CO-97 | Service included in another service (bundling) | Check add-on code rules (e.g., 90785, 90833) and payer edits before submission. |
| CO-4 | Modifier missing or inconsistent with the procedure | Use payer-specific telehealth modifier and place-of-service rules. |
| CO-16 | Claim missing information | Scrub claims for rendering provider, taxonomy, referring provider and demographics. |
| CO-29 | Timely filing limit expired | Submit within 48 hours and work rejections daily so claims never age out. |
| CO-18 | Duplicate claim | Check claim status before resubmitting. Use corrected-claim frequency codes properly. |
Track denials the right way
Look at denial rate by payer, by clinician and by CPT code. One payer or one code often causes most of the problem. A practice with 1,000 claims a month and a 15% denial rate has 150 claims to rework every month. Even if most get paid in the end, that delays cash and uses staff time.
Fix the cause, not just the claim
Resubmitting fixes one claim. Changing the intake checklist, the note template or the authorization workflow fixes the next hundred. The best denial management does both.