If you run a mental health or behavioral health practice, the billing landscape in 2026 looks different than it did even 12 months ago. Telehealth modifier rules have shifted. Parity enforcement under MHPAEA is generating new denial patterns. Prior authorization requirements for extended therapy sessions are tightening across most commercial payers.
The result: practices that were billing smoothly in 2024-2025 are suddenly seeing denial rates climb without understanding why. The codes haven't changed. The services haven't changed. What's changed is how payers are processing and scrutinizing mental health claims.
Here are the three biggest shifts in mental health billing in 2026 and what your practice needs to do about each one.
Telehealth was supposed to get simpler after the pandemic. It hasn't. The temporary flexibilities that made telehealth billing straightforward during 2020-2022 have been replaced by a patchwork of payer-specific rules that catch practices off guard every week.
The core problem: there are now multiple ways to indicate a telehealth service on a claim, and different payers require different combinations.
| Indicator | What It Is | Who Requires It |
|---|---|---|
| Modifier 95 | Synchronous telehealth service (real-time audio/video) | Most commercial payers, some Medicare Advantage plans |
| Modifier 93 | Audio-only telehealth service | Medicare, some state Medicaid programs, select commercial payers |
| Modifier GT | Via interactive audio/video (legacy modifier, being phased out) | Some Medicaid programs, legacy payer systems |
| POS 10 | Place of service: Telehealth in patient's home | Medicare requires POS 10 when patient is at home |
| POS 02 | Place of service: Telehealth (patient at qualifying facility) | Medicare when patient is at an originating site |
The confusion comes from the combinations. Medicare wants POS 10 + Modifier 95 for a video visit with the patient at home. UnitedHealthcare wants Modifier 95 + POS 11 (office) with the telehealth modifier indicating the delivery method. Aetna accepts either POS 02 or POS 10 but requires Modifier 95 on the CPT line. BCBS varies by state plan.
For a multi-payer mental health practice doing 60% of visits via telehealth, this means the same 90837 therapy session gets billed differently depending on the payer. One wrong modifier or POS code and the claim denies.
The expensive mistake: Practices that bill all telehealth visits with POS 02 + Modifier GT (the 2020-era approach) are seeing increasing denials as payers update their systems. GT is being phased out by most commercial payers. If your billing team hasn't updated telehealth modifier protocols since 2023, you're likely generating preventable denials on every telehealth claim.
Build a payer-specific telehealth billing matrix. For each payer in your top 10 by volume, document: which modifier they require (95, 93, or GT), which place of service code they require (02, 10, or 11), whether they distinguish between audio-only and audio/video, and any state-specific overrides.
This matrix should be updated quarterly because payers are still adjusting their telehealth policies. What works in January may not work in April.
The Mental Health Parity and Addiction Equity Act (MHPAEA) requires health plans to cover mental health and substance use disorder benefits at the same level as medical/surgical benefits. In theory, this means a plan can't impose stricter prior authorization requirements, visit limits, or copays on mental health services than on comparable medical services.
In practice, enforcement has been inconsistent for years. But 2025-2026 has seen a significant increase in regulatory attention. The Department of Labor issued final rules in 2024 requiring health plans to perform comparative analyses of their nonquantitative treatment limitations (NQTLs). Plans that fail these analyses are being required to change their policies.
This is creating a transitional period where payer policies are shifting mid-year. What does that look like for your billing team?
Prior authorization requirements changing without notice. Some plans that previously required prior auth for 90837 after 12 sessions are removing those requirements to comply with parity rules. Others are restructuring their auth requirements rather than removing them. Your billing team submits an auth request that's no longer required and wastes 20 minutes. Or worse, they skip an auth request that's been restructured and the claim denies.
Retroactive policy changes. When a payer modifies their mental health benefit policies to comply with MHPAEA, some changes apply retroactively. Claims denied under the old policy may now be payable under the new one. If your billing team isn't monitoring payer policy updates, you may have recoverable revenue sitting in your denied claims backlog that wasn't recoverable when it was originally denied.
Network adequacy disputes. Some payers are narrowing their behavioral health networks while simultaneously claiming to expand access. If your practice is out-of-network with a plan that doesn't have adequate in-network behavioral health providers, the payer may be required to cover your services at in-network rates under parity rules. This is complex to bill but represents significant revenue for out-of-network practices.
Action item: Review your denied claims from the last 6 months filtered by payer. If any payer has recently updated their mental health benefit policies (check their provider bulletins), resubmit previously denied claims that may now be covered under the updated policy. This is free revenue from claims you already wrote off.
CPT 90837 (individual psychotherapy, 53+ minutes) has always been a target for prior authorization requirements. In 2026, several major payers have tightened their auth protocols for 90837 specifically, while leaving 90834 (38-52 minutes) relatively untouched.
The pattern is clear: payers want to push providers from 60-minute sessions to 45-minute sessions. The reimbursement difference between 90834 and 90837 is typically $30-$50 per session. For a therapist seeing 25 patients per week, that difference adds up to $39,000-$65,000 per year in reduced revenue if they downcode from 90837 to 90834.
Session time documentation. Payers are requiring precise documentation of therapy time. A note that says "60-minute session" without documenting what occurred during the full 53+ minutes triggers a CO-21 or medical necessity denial. The note needs to substantiate why a full 60-minute session was clinically necessary rather than a 45-minute session.
Authorization expiration. Many payers authorize a fixed number of 90837 sessions (typically 12-20) and require re-authorization. Practices that don't track session counts against their authorized limit get denied when they exceed the authorized number. The denial often comes weeks after the service was provided, making it difficult to obtain retro-authorization.
Medical necessity criteria. Some payers are applying more stringent medical necessity criteria to 90837. They want to see documented clinical justification for why a longer session is needed. A patient with uncomplicated anxiety may not meet the medical necessity threshold for 90837 under the new criteria, even though 60-minute sessions are clinically appropriate in the provider's judgment.
Scenario: A 3-therapist practice bills 75 sessions per week. Prior to 2026, they billed 80% as 90837 and 20% as 90834. Average reimbursement: 90837 = $145, 90834 = $105.
Weekly revenue (old mix): 60 x $145 + 15 x $105 = $10,275
After payer pressure shifts mix to 50/50: 37 x $145 + 38 x $105 = $9,355
Annual revenue impact: ($10,275 - $9,355) x 48 weeks = -$44,160/year
That revenue loss isn't from denials. It's from providers pre-emptively downcoding to avoid denials. The payer's prior auth friction achieves its goal without ever formally denying a claim.
Document clinical necessity explicitly. Every 90837 note should include a statement addressing why the extended session length was required. "Patient presented with acute suicidal ideation requiring extended safety assessment and crisis intervention" supports medical necessity. "60-minute therapy session" does not.
Track authorization balances. Build a tracking system (spreadsheet, EHR task, or billing software feature) that counts authorized sessions per patient per authorization period. Set an alert at 80% utilization so your team can request re-authorization before the limit is reached, not after.
Know when to bill 90834. Not every session needs to be 90837. If the clinical encounter genuinely falls in the 38-52 minute range, bill 90834. Routinely upcoding 45-minute sessions as 90837 invites audit scrutiny and undermines your credibility when you do need to bill 90837 for genuinely extended sessions.
Appeal medical necessity denials aggressively. When a 90837 is denied for medical necessity, appeal with a detailed clinical letter. Reference the patient's diagnosis severity, treatment complexity, and specific clinical activities that required the extended session. Include relevant clinical guidelines (APA Practice Guidelines, for example) that support 60-minute sessions for the patient's condition. Many medical necessity denials are overturned on appeal when clinical documentation is strong.
There's a fourth issue that doesn't get enough attention: credentialing for multi-state telehealth practices. Mental health is the specialty most affected by multi-state practice because telehealth has expanded geographic reach beyond the provider's physical location.
A therapist licensed in three states who sees patients via telehealth needs to be credentialed with payers in all three states. Each state has different payer networks, different Medicaid programs, and different credentialing timelines. A credentialing gap in one state means claims deny with CO-185 or CO-206 for every patient in that state until enrollment is completed.
The credentialing timeline for behavioral health providers has lengthened in 2026. What used to take 60-90 days is now taking 90-120 days with some payers, particularly Medicaid managed care plans. Practices that add a new state without starting the credentialing process 4 months in advance end up seeing patients for 3-4 months before claims can be submitted, creating a massive AR backlog.
Best practice: Start credentialing 120 days before you plan to see patients in a new state. Submit applications to all payers simultaneously rather than sequentially. Track every application with expected completion dates and follow up weekly after the 60-day mark. A single credentialing gap can cost $15,000-$30,000 in denied claims before it's resolved.
Audit your telehealth modifiers. Pull 10 telehealth claims from each of your top 5 payers. Verify that the modifier and POS code combination matches the payer's current requirements. If you find inconsistencies, update your billing protocols immediately.
Review payer policy bulletins. Check for MHPAEA-related policy changes from your top payers in the last 6 months. If policies have changed, review previously denied claims for potential resubmission.
Track your 90837 vs 90834 mix. Calculate the percentage of sessions billed as 90837 versus 90834 for the last 3 months compared to the prior year. If the mix has shifted toward 90834, determine whether it's clinically driven or denial-driven. If denial-driven, you're losing revenue to payer pressure that can be recovered through better documentation and appeals.
Verify credentialing status in every state you practice. Confirm active enrollment with every payer in every state where you see patients. One lapsed enrollment can generate months of CO-185 denials before anyone notices.
Use our Denial Code Lookup Tool to research any denial codes you're seeing. And if your denial rate has climbed in 2026 without an obvious explanation, the changes outlined above are likely the cause.
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