In the windowless back offices of state Medicaid programs from Indianapolis to Augusta, auditors have spent the past two years poring over session notes, treatment plans, and billing codes. What they have found is prompting a sweeping reassessment of how America pays for autism therapy—and raising uncomfortable questions about an industry that has grown at a rate few could have anticipated.
Applied behavior analysis, or ABA, has become the dominant therapeutic intervention for children diagnosed with autism spectrum disorder. The therapy, which uses structured techniques to reinforce communication and social skills, has expanded dramatically in the past decade as insurance mandates have spread across all fifty states. In Indiana alone, Medicaid spending on ABA grew from $21 million in 2017 to $611 million in 2023—a nearly thirty-fold increase in just six years.
Now the bill is coming due. A coordinated series of federal audits by the U.S. Department of Health and Human Services Office of Inspector General has uncovered widespread documentation and billing failures across state Medicaid programs. The findings have already identified more than $120 million in confirmed improper payments across Indiana, Wisconsin, and Maine, with additional state audits still underway. For providers—particularly small and mid-sized practices that lack the compliance infrastructure of larger platforms—the implications are stark.
The Audit Cascade
The federal government’s scrutiny of ABA billing began in earnest in late 2024. Indiana was the first state to have its results published, and the numbers were staggering. The OIG found at least $56 million in improper fee-for-service Medicaid payments for ABA services provided to children with autism during 2019 and 2020, with an additional $76.7 million in payments flagged as potentially improper. Every single one of the hundred sampled enrollee-months contained claims that were either improper or potentially improper—a finding that suggested not isolated bad actors but systemic failures in documentation and oversight.
Wisconsin followed in July 2025 with similarly troubling results: $18.5 million in confirmed improper payments and an estimated $94.3 million in potentially improper claims. Again, all hundred sampled cases showed problems. The most recent audit, released in late January 2026, found Maine had made at least $45.6 million in improper payments for rehabilitative and community support services for children with autism. The federal government is now calling for Maine to refund $28.7 million.
The pattern across states has been remarkably consistent. Auditors have flagged session notes that fail to support the billed CPT codes, documentation that does not match the number of units claimed, missing provider signatures, and services delivered by staff lacking proper credentials or supervision. In some cases, providers billed for what auditors termed “impossible billing”—claiming more than twenty-four hours of service for a single patient in a single day. Others submitted claims for therapy purportedly delivered on Christmas Day or other major holidays, raising questions about whether services actually occurred.
The federal OIG currently has eight state audits in its ABA series, with three completed (Indiana, Wisconsin, and Maine), one canceled, and four additional investigations announced but not yet posted. The message to state Medicaid administrators is clear: the problems uncovered thus far are likely not unique.
A Gold Rush and Its Consequences
To understand how the ABA industry arrived at this moment, it helps to trace the arc of its growth. A decade ago, ABA therapy existed largely at the margins of the healthcare system. Insurance coverage was spotty, Medicaid reimbursement was limited, and the therapy remained unfamiliar to most pediatricians. That began to change as state legislatures, responding to advocacy from autism families, enacted coverage mandates. By 2022, every state Medicaid program covered ABA services.
The money followed. According to a recent analysis by Trilliant Health, overall ABA visits increased 267 percent from 2019 to 2024, with Medicaid-covered services growing even faster—up 298 percent over the same period. The U.S. ABA market was valued at approximately $8 billion in 2025, with projections suggesting it will approach $10 billion by 2030. Private equity investors, recognizing the sector’s growth trajectory, poured capital into the space, driving consolidation and the emergence of multi-state platform companies. Autism-focused platforms now command EBITDA multiples of twelve to fifteen times—among the highest in behavioral health.
But the rapid expansion outpaced the development of compliance infrastructure. In Indiana, the number of Medicaid-enrolled ABA therapists grew from 797 in 2020 to 2,534 by the end of 2024. Training programs struggled to keep pace with demand. Billing practices varied widely. Some providers billed at rates exceeding $900 per hour before states established fee schedules. The result was a system that, in the words of one state official, grew “faster than oversight could follow.”
Small Providers, Big Exposure
While the federal audits have focused on state-level improper payments, the financial consequences ultimately flow downward to individual providers. And here, the disparity between large platforms and small practices becomes painfully apparent.
Large, private equity-backed ABA companies typically employ dedicated compliance teams, sophisticated billing software, and internal audit functions designed to catch documentation errors before claims are submitted. When audits arrive, they have the resources to respond systematically and the legal counsel to navigate appeals. Smaller providers—the single-clinic practices and family-owned operations that still serve many communities—often lack these safeguards.
“Some networks have pulled back hundreds of thousands of dollars from individual practices,” observed Zach Rosen, CEO of Brellium, a compliance technology company serving ABA providers. “As scrutiny increases across both commercial payers and Medicaid programs, building a culture of compliance isn’t just a best practice. It’s essential for protecting revenue and sustaining your organization.”
The mechanisms of recoupment can be brutal. Insurance companies and Medicaid programs often have windows of several years to pursue clawbacks—meaning providers can face demands for repayment on services delivered long ago. For a small practice operating on thin margins, a six-figure recoupment demand can threaten solvency. The cash that was spent on staff salaries, rent, and equipment must now be returned, regardless of whether the underlying services were actually provided.
Beyond Medicaid: Commercial Payer Scrutiny
The federal audits have captured headlines, but providers report that commercial insurers have also intensified their retroactive review activity. Special Investigation Units at large multi-state insurers are increasingly deploying data analytics to identify billing anomalies—providers whose patterns diverge from peers, practices with unusually high utilization, or claims that suggest possible upcoding.
These commercial audits often proceed quietly, with providers receiving letters requesting documentation for claims submitted months or years earlier. The burden of proof shifts to the provider, who must demonstrate that every billed unit was properly documented and medically necessary. Failures to meet documentation requirements can result in recoupment demands that accumulate quickly.
The legal framework governing clawbacks varies by state, with some jurisdictions limiting insurers’ recoupment windows or requiring timely notification. But the trend is clear: payers are no longer content to pay claims and move on. Post-payment review has become a significant source of cost containment—and risk for providers.
The Enforcement Horizon
The OIG audits represent civil findings of improper payments, not criminal charges. But they often serve as precursors to more aggressive enforcement. State Medicaid Fraud Control Units have publicly identified ABA therapy as an enforcement priority. At a recent American Health Lawyer’s Association Fraud and Compliance Forum, Kevin Lownds, Division Chief of the Massachusetts Attorney General’s Medicaid Fraud Control Unit, described ABA as an area where “fraud and abuse is rampant,” noting that high reimbursement rates have attracted bad actors to the space.
Massachusetts has already demonstrated its willingness to pursue criminal cases. In June 2025, the state Attorney General’s office indicted an autism service provider that allegedly fabricated documentation to support over $1 million in false claims for ABA services that were never provided. In October 2023, the state reached settlements totaling more than $2.5 million with two providers accused of billing for services not rendered or not properly supervised.
The distinction between documentation errors and fraud can be legally significant but practically murky. Providers who genuinely delivered services but failed to document them properly face the same recoupment demands as those who may have billed fraudulently. The burden falls on the provider to prove their innocence—a costly and time-consuming process even when the outcome is favorable.
What Comes Next
The ABA industry now faces a period of adaptation. Compliance officers have become essential hires. Practice management software increasingly includes real-time documentation auditing and billing verification. Industry groups like the Council of Autism Service Providers are hosting webinars on the OIG findings and their implications.
States, too, are responding. Indiana has initiated a program integrity review of Medicaid claims paid for ABA therapy from 2022 through 2025, with mandatory compliance training for providers found to have overbilled. Wisconsin and Maine have agreed to implement corrective actions recommended by the OIG, including enhanced provider guidance and periodic post-payment reviews.
The broader question is whether the current payment model—which reimburses providers based on billable hours rather than patient outcomes—can sustain an industry that has grown so rapidly. Payers and investors are increasingly pushing for value-based arrangements that tie reimbursement to measurable progress. But the field has yet to agree on what outcomes should be measured or how.
“The current payment structure creates misaligned incentives,” a recent Trilliant Health report observed. “Providers benefit financially from maximizing billable hours regardless of whether treatment produces meaningful improvements.” Without systematic tracking of treatment outcomes, the report continued, “states lack the data necessary to determine whether spending increases reflect appropriate expansion of services or systemic problems.”
For now, the immediate imperative for providers is survival. The audits have made clear that documentation practices once considered adequate no longer meet scrutiny. Session notes must explicitly describe the services provided and the goals addressed. Billing must precisely reflect the time and nature of services delivered. Supervision must be documented contemporaneously, not reconstructed after the fact.
The families who depend on ABA services for their children watch these developments with understandable anxiety. Any disruption to provider networks—whether through practice closures, reduced Medicaid coverage, or tighter utilization controls—ultimately affects their access to care. The challenge for policymakers is to root out genuine fraud and correct billing errors while preserving access to services that, for many children, represent their best chance at meaningful developmental progress.
The reckoning now underway will reshape an industry that grew faster than anyone anticipated. What emerges on the other side—leaner, more accountable, perhaps more equitable in its distribution of resources—remains to be seen. But the era of unchecked expansion is over. The auditors have arrived, and they are just getting started.
