Vermont Banned Concurrent ABA Billing. Revenue at Affected Clinics Dropped 17%. Your State Could Be Next.

Revenue Dropped 17% and Nobody Changed a Rate

In November 2025, Vermont’s Department of Vermont Health Access (DVHA) issued an ABA coding update. Effective January 1, 2026, Vermont Medicaid would no longer reimburse for CPT codes 97153 and 97155 billed simultaneously for the same patient.

That’s the concurrent billing ban. It took effect with about six weeks of runway.

Revenue at Keene Perspectives, an ABA clinic in Hartford, Vermont, dropped 16% in January and February — the first two full months under the new policy. Other Vermont providers reported per-client payment reductions of 15% to 50%. The clinics losing the most were those with heavier BCBA supervision time per session — precisely the ones doing high-quality work.

Vermont didn’t cut its reimbursement rate. It changed a billing rule. And the financial impact hit as hard as any rate cut we’ve covered this year.

Children are being discharged early. One family lost six planned months of services when their clinic’s economics could no longer support the caseload.

This is not a Vermont story. Vermont is the outcome. The story is the OIG audit that triggered it — and that audit applies to every state where you currently bill both codes on the same claim.

What Concurrent Billing of 97153 and 97155 Actually Means

In the standard ABA session model:

• A behavior technician (BT or RBT) runs the session directly with the child
• A BCBA supervises — directing the technician in real time, adjusting protocols, analyzing data

The CPT codes for this:

• 97153 (Adaptive Behavior Treatment by Protocol, Technician Administered): billed for the tech’s face-to-face time with the child
• 97155 (Adaptive Behavior Treatment with Protocol Modification, by Physician or Other QHP): billed when the BCBA is actively directing and modifying the session

When both happen at the same time — the tech is delivering treatment while the BCBA is directing — billing both 97153 and 97155 for the same time period is called concurrent billing.

The AMA’s coding framework has historically supported this. The ABA Coding Coalition, CASP, and ABAI have all stated that concurrent billing of 97153 and 97155 is an “expected component of the AMA CPT codes” — because the two providers are genuinely delivering different, simultaneous services. The BCBA isn’t doing what the tech is doing. They’re doing different things at the same time.

Most state Medicaid programs and commercial payers allow it, at least implicitly, by not prohibiting it.

Vermont just prohibited it.

The Wisconsin OIG Audit That Triggered Vermont’s Decision

In 2025, the HHS Office of Inspector General published its audit of Wisconsin’s fee-for-service Medicaid ABA payments. OIG found that Wisconsin had made at least $18.5 million in improper payments — and embedded in the findings was a specific flag: Wisconsin had no clear concurrent billing policy, and the absence of that policy had enabled billing patterns the OIG characterized as improper.

The OIG report noted that Wisconsin’s own guidance had muddied the waters — the state told providers that 97155 could be billed when a BCBA merely observed a technician, even without any protocol modification. That interpretation inflated 97155 billing. And without a clear concurrent billing rule, overlapping 97153 and 97155 claims contributed to the improper payment tally.

Vermont read that audit and drew a direct line.

The DVHA coding update published in November 2025 stated its rationale explicitly: Wisconsin OIG identified concurrent billing as a contributing factor. Without a clear Vermont policy, the state faced potential “multimillion-dollar liabilities for the state and providers.” Banning the practice was cleaner than trying to define acceptable and unacceptable concurrent billing within a policy that auditors could second-guess.

Vermont’s Medicaid policy director characterized concurrent billing as “essentially duplicating payments” — billing twice for one child’s time, once for the tech and once for the BCBA supervising that tech.

CASP Says Vermont Is Wrong. Oregon Took the Opposite Approach.

Vermont’s interpretation is contested — directly and by name.

CASP — the Council of Autism Service Providers — launched an advocacy campaign challenging Vermont’s policy change. CASP’s position: billing 97153 and 97155 concurrently is consistent with AMA CPT guidance because the services are genuinely distinct. The BCBA and the tech are doing different work at the same time. This is not double-billing for the same service; it is billing for two different services happening simultaneously.

The AMA CPT supplemental guidance is on CASP’s side in principle: it explicitly states that 97153 and 97155 may be reported concurrently when the qualified health professional (BCBA) is directing a technician who is simultaneously running a session with the client present.

Oregon landed on a different policy than Vermont. In January 2024, the Oregon Health Authority issued an explicit concurrent billing announcement: 97153 and 97155 can be billed at the same time, provided:

1. Both services are medically necessary and clinically appropriate
2. The technician’s activities are within the scope of the supervision
3. The concurrent units do not exceed four units (one hour) for both codes combined
4. Documentation meets Oregon Administrative Rule 410-172-0620 requirements

Oregon allowed concurrent billing with documentation guardrails. Vermont banned it outright. The AMA says it’s supported by coding standards. The OIG found it contributed to improper payments in Wisconsin.

Every ABA practice in a state that hasn’t explicitly addressed concurrent billing is sitting in the middle of this disagreement — and the OIG is the one with subpoena power.

Why “My State Hasn’t Said Anything” Is Not Safe

The OIG’s multi-state ABA audit series launched in 2022, targeting seven states. Four audits are complete:

Three more state audits are in progress. The OIG hasn’t published which states they are — but it has confirmed the series continues.

Every state audited has had concurrent billing as one dimension of the improper payment findings. Every state has found a 100% deficiency rate across sampled claims. The pattern is not a regional fluke. It’s an industry-wide compliance failure that the OIG is systematically documenting.

When an OIG audit finds improper payments in a state, the state Medicaid program faces federal pressure to refund the federal share. To prevent future findings, states have two options: define a policy that limits concurrent billing to documented, medically justified scenarios, or ban it.

Vermont chose option 2. It’s faster and easier to audit. Other states that get audited will face the same choice.

States without explicit concurrent billing policies are not in a better position than Vermont was before January 1. They’re in the same position Wisconsin was in when it was audited: no clear policy, OIG exposure, and the audit result now public record.

Modeling the Financial Impact on Your Practice

The 16–17% overall revenue drop at Vermont clinics reflects how much of their Medicaid billing involved concurrent 97153 + 97155. Practices with heavier BCBA supervision time per session — more hours of 97155 per week — took bigger hits. The 50% per-client reduction figure reflects clients where a BCBA was supervising through most of the session.

For a concrete model:

A practice billing $80,000/month in Medicaid, where 20% of total units are 97155 billed concurrently with 97153, would lose approximately $16,000/month if those concurrent 97155 claims were eliminated — a 20% revenue reduction without any change in services delivered.

That is not a hypothetical. That’s Vermont, with real clinics and real client discharges.

The practices most exposed are those with:

• Heavy BCBA supervision models (BCBAs present in session frequently)
• Many clients requiring intensive, real-time protocol adjustments
• Billing 97155 for a significant share of total service hours

If that describes your practice, you should know your concurrent billing exposure number before you hear about a bulletin from your state Medicaid program.

Action Steps for This Week

1. Pull your concurrent billing data. Run a report for the past 90 days showing every claim where 97153 and 97155 were billed for the same patient on the same day in overlapping time windows. Calculate the dollar volume of 97155 billed concurrently with 97153. That number is your maximum exposure if your state adopts Vermont’s policy.

2. Check your state Medicaid provider manual. Search for “concurrent billing,” “97153 97155,” and “overlapping codes.” If your state has an explicit policy allowing concurrent billing with conditions (like Oregon), confirm you’re meeting those conditions. If your state has no policy, you’re in the same position Vermont was — and you’re in a state the OIG may audit.

3. Audit your 97155 documentation. OIG findings in Wisconsin included a specific finding: 97155 was being billed for mere BCBA presence, without documented protocol modification. Your 97155 session notes need to show that the BCBA was actively directing and adjusting the session — not just that they were in the room. Documentation that reads “supervisor observed session” is not sufficient for 97155. Documentation needs to describe the specific clinical decision, protocol change, or real-time guidance provided.

4. Understand your state’s concurrent billing exposure relative to Oregon’s benchmark. Even if your state hasn’t addressed concurrent billing, Oregon’s four-unit limit is a reasonable practical ceiling for concurrent 97155 billing per session. Practices billing more 97155 than 97153 for the same session are outliers by any reasonable clinical model.

5. Brief your billing team on this issue. If your RCM vendor or billing staff hasn’t flagged Vermont’s policy change and the Wisconsin OIG finding as relevant to your billing practices, that’s a gap. This is actively being used as a basis for state Medicaid policy changes.

The Pattern Continues

Vermont’s concurrent billing ban is one piece of the same pressure system we’ve been tracking:

• The Colorado OIG audit — the fourth in the OIG’s multi-state ABA audit series — has found improper payments in 100% of sampled claims across every state audited, and Wisconsin’s concurrent billing finding is now driving state policy changes
• Documentation failures by CPT code are the primary mechanism for those findings — and concurrent billing without adequate 97155 documentation is exactly that kind of failure
• Georgia’s CareSource rate cut and New York’s 25% reduction reflect states and payers pressing ABA costs from every angle simultaneously

Billing rule changes can hit revenue faster than rate cuts. A rate cut requires a rulemaking process, a public notice period, and sometimes a state plan amendment. A billing policy change requires a bulletin and an effective date.

Vermont gave six weeks of notice. It cost some providers 17% of their revenue.

The action items above don’t require waiting for your state to act. Pull the data now. The number you find is the risk you’re carrying today.

StreamABA helps ABA practices stay audit-ready and compliant as payer and regulatory requirements change. Questions about your concurrent billing exposure or documentation practices? Reach out at [email protected] — we’ll walk through it with you.

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