We audit a lot of behavioral health, ABA, mental health, and substance use disorder practices. The pattern is almost always the same: 8 to 12 percent of net revenue is sitting in denials that nobody had time to rework.
It’s not because the billing team is bad. It’s because there aren’t enough hours in the day. The team is fighting today’s clean claims and prior auths; yesterday’s denials pile up in a queue that never quite gets worked. Eventually the appeal window closes, the claim is written off, and the practice never sees the money.
If you run revenue cycle for an ABA, behavioral health, or SUD practice, this article is the short version of what we find when we audit a denials sample. Five patterns, why they happen, and what’s usually recoverable.
1. ABA: 97153 unit-count denials and 97155 supervision-ratio rejections
ABA practices lose more revenue to authorization-related denials than to any other category. The two we recover most often:
- 97153 unit-count denials. Authorization issued for 30 units a week; the practice delivered 32; the extra 2 get denied. Most billing teams write them off automatically instead of pursuing a corrected auth or a peer-to-peer.
- 97155 supervision-ratio undocumented. The BCBA didn’t co-sign or didn’t document the 1:1 supervision time on a session that required it. Payer denies. Most teams don’t rework these because they assume the documentation gap is permanent — but corrected documentation is often allowed within a window.
What we usually recover: 30 to 50 percent of denied 97153 units when caught within the appeal window; significant chunks of 97155 denials when supervision documentation can be cured.
2. Mental Health: 90837 downcoded to 90834
One of the most quietly expensive downcodes in mental health billing. Provider documents a 53-minute therapy session (90837). Payer downcodes to 90834 (38-52 minutes) because documentation didn’t explicitly support the longer session. Reimbursement drops by roughly 30 to 40 percent depending on the payer.
The billing team often doesn’t appeal because they assume downcodes are final. They’re not — when the documentation actually supports the longer session and the appeal is filed in time, recovery rates are high.
What we usually recover: 60 to 80 percent of downcodes when the clinical note supports the original 90837 and the appeal is well-documented.
3. Telehealth: POS-02 vs POS-10 mismatches
Since the federal telehealth place-of-service rules shifted, behavioral health practices are seeing clean claims denied over POS codes. Common mistakes:
- POS-02 used when POS-10 was required (patient in home).
- POS-10 used when POS-02 was required (patient at a non-home location).
- Modifier 95 or GT missing or used incorrectly.
Most denials of this kind are fully recoverable as corrected claims. The blocker is volume — nobody on the billing team has time to go pull each chart, confirm patient location, and resubmit.
What we usually recover: 80 to 95 percent of POS-mismatch denials when the documentation supports the corrected POS.
4. SUD: UR and level-of-care denials past the appeal window
Substance use disorder programs lose more revenue to utilization review and level-of-care denials that never get appealed in time than to almost any other category. Payer denies a continued-stay request because the UR submission was late or incomplete. By the time the billing team gets around to it, the 30-day appeal window is gone.
The other quiet revenue leak in SUD: drug-screen claims bundled wrong (G0480 through G0483). The codes are stratified by complexity; many billing teams default to the lower-complexity code when the higher one is supportable.
What we usually recover: UR/LOC appeals are time-sensitive but recoverable at 40-60 percent when within window. G0480-G0483 corrected claims recover at 70+ percent.
5. Parity-violation denials that should have been appealed
Behavioral health practices have a federal Mental Health Parity protection that requires payers to apply the same coverage rules they apply to medical/surgical claims. A common pattern: payer denies a behavioral health claim citing a limit that wouldn’t apply to a comparable medical claim. The denial is technically appealable on parity grounds, but the billing team accepts it as final because parity appeals require legal-aware language.
What we usually recover: Parity-violation denials, when appealed correctly, have one of the highest reversal rates of any denial category — often 70 percent or higher.
The math on what this costs you
Take a practice doing $5M a year in net revenue. The 8-12% denial leak that’s typical for behavioral health and ABA practices puts $400K to $600K a year in recoverable revenue sitting in a denials queue that’s never fully worked. Even capturing half of that is $200K-$300K of margin you’re currently leaving on the table.
That’s not a billing problem you can hire your way out of. It’s a workflow and bandwidth problem. The denials that never get worked don’t get worked because the team has bigger fires.
Get a free audit of your denials
If your billing team is too busy fighting today’s fires to work yesterday’s denials, we’ll audit a sample of your aged AR and denied claims for free. We hand you the findings — what’s recoverable by payer and code, with dollar amounts — and you decide what to do with it.
- No cost.
- No contract.
- No switching billers.
- You keep the report either way.
We do this because eight out of ten audits surface enough recoverable revenue that the engagement pays for itself many times over. But you’re under no obligation, and the audit is yours to act on however you want — including handing it to your current biller.
Grab 15 minutes here to scope the audit →
Or reply directly to this post with the size of your aged AR over 90 days and we’ll come prepared with a tailored sample of what we’d review.
About Revenant Care
We run billing for behavioral health, ABA, mental health, and SUD practices across the United States. US-managed, specialty-trained billers who work the denials and aged AR most practices write off.
Practices ready to talk: book a 15-minute call.