Last updated: October 2026 · Educational guide, not billing advice.
Roughly a quarter of mental health claims are denied on first submission. The frustrating part: most denials trace back to a handful of preventable causes. Here are the seven that dominate, and the one habit that defuses each.
Coverage ended, the plan changed, or the client's deductible reset in January. Fix: re-verify benefits before every session, not once at intake. A 60-second check beats a 60-day write-off.
Many plans require auth for 90837, for extended sessions, or after a visit-count threshold. Fix: track authorized units and expiration dates per client, with an alert at 80% consumed.
Billing 90837 for a 47-minute session, or 90834 for a 30-minute check-in. Fix: document start/stop times and let the documented duration pick the code — not the other way around.
Modifier 95 vs GT, place of service 02 vs 10 — rules differ by payer and changed repeatedly after the public-health emergency ended. Fix: maintain a per-payer cheat sheet and re-check it quarterly.
Medical necessity denials: the ICD-10 code doesn't justify the frequency or length of sessions in the payer's policy. Fix: your note should connect symptoms → intervention → progress, in the client's own clinical language.
Every payer has a filing window (commonly 90–180 days). Credentialing delays and batch-submission habits eat it. Fix: submit weekly, and calendar the filing deadline the day a claim is rejected, not the day it's finally denied.
Resubmissions flagged as duplicates, or claims denied because another plan is primary (coordination of benefits). Fix: correct with the proper frequency code instead of resubmitting, and ask about other coverage at every intake and every January.