By Matt Harrington, BCBA · Behaviorist Book Club · April 2026 · 12 min read

A BCBA's Guide to the Ethics of ABA Co-Treatment Models

Overview & Clinical Significance

The co-treatment model in ABA service delivery, where behavioral services are provided simultaneously or in close coordination with services from another discipline such as speech-language pathology or occupational therapy, has generated significant discussion and debate within the field. As the healthcare landscape increasingly emphasizes integrated, client-centered care, co-treatment offers the potential for enhanced collaboration, more efficient service delivery, and improved client outcomes. However, it also introduces complex ethical questions about billing practices, scope of competence, and the boundaries of interdisciplinary collaboration.

The clinical significance of co-treatment models lies in their potential to address the reality that many individuals receiving ABA services have complex needs that span multiple domains. A child who receives both ABA and speech therapy, for example, may benefit from sessions where both professionals work together to target communication goals within a behavioral framework. The speech-language pathologist contributes expertise in language development and communication modalities, while the behavior analyst contributes expertise in reinforcement, prompting, and systematic instruction. When these approaches are integrated during a single session, the client may experience more cohesive, efficient services than they would from two separate sessions addressing overlapping goals independently.

However, the promise of co-treatment must be balanced against legitimate concerns about how these services are structured, documented, and billed. The question of whether co-treatment sessions should be billed separately by each discipline, what documentation is required to support co-treatment billing, and how to ensure that each professional is genuinely contributing their unique expertise rather than simply being present during another professional's session are all issues that require careful ethical analysis.

The 2022 updates to the BACB Ethics Code provide a framework for evaluating co-treatment models, particularly in the areas of billing practices, interdisciplinary collaboration, and scope of competence. These ethical guidelines help behavior analysts navigate the complex terrain of co-treatment by establishing standards for documentation, billing accuracy, and professional conduct in collaborative settings.

For ABA organizations and individual practitioners, the decision to implement co-treatment models involves weighing clinical benefits against administrative complexity, ethical requirements, and potential risks. Organizations that implement co-treatment must develop clear policies and procedures that ensure ethical compliance while maximizing the clinical benefits of collaborative service delivery. Individual BCBAs must be prepared to evaluate co-treatment opportunities critically, contribute their unique expertise effectively, and maintain rigorous documentation standards.

Background & Context

The co-treatment model has its roots in rehabilitation medicine, where professionals from multiple disciplines have long worked together during shared treatment sessions. Physical therapists and occupational therapists, for example, frequently co-treat when addressing goals that span both disciplines. This model has been extended to ABA and speech-language pathology, ABA and occupational therapy, and other discipline combinations serving individuals with autism and developmental disabilities.

The debate surrounding co-treatment in ABA intensified as insurance companies and regulatory agencies began scrutinizing billing practices. Several concerns have been raised about co-treatment billing: whether it constitutes double-billing when two professionals bill for the same time period, whether each professional can demonstrate unique and necessary contributions to each co-treatment session, whether documentation adequately supports the distinct services provided by each discipline, and whether co-treatment is being used for genuine clinical benefit or primarily as a billing strategy.

Insurance companies have responded to these concerns with varying policies. Some payers explicitly allow co-treatment billing under specific documentation requirements, while others prohibit billing for overlapping service times. Some require prior authorization for co-treatment sessions, while others review co-treatment claims retrospectively during audits. This inconsistency across payers creates challenges for organizations that want to implement co-treatment models while ensuring compliance with billing requirements.

The January 2022 updates to the BACB Ethics Code addressed several issues relevant to co-treatment. The code emphasizes the importance of accurate billing practices, requiring that behavior analysts bill only for services they have personally provided and that billing accurately represents the nature and extent of services delivered. The code also strengthens provisions related to interdisciplinary collaboration, encouraging behavior analysts to work effectively with other professionals while maintaining clear boundaries around scope of practice.

The clinical evidence regarding co-treatment outcomes is limited but growing. Some practitioners report that co-treatment sessions produce better generalization of communication skills, more efficient use of therapy time, and higher family satisfaction compared to separate sessions addressing similar goals. However, rigorous research comparing co-treatment and separate treatment models is scarce, making it difficult to draw definitive conclusions about relative effectiveness.

The practical implementation of co-treatment varies significantly across settings and organizations. Some co-treatment models involve both professionals actively working with the client simultaneously throughout the session. Others involve a more sequential approach, where the professionals alternate between leading and supporting roles during different portions of the session. Still others involve one professional primarily working with the client while the other consults, observes, or provides intermittent input. The specific structure of the co-treatment session has implications for both the clinical value and the billing defensibility of the service.

Clinical Implications

Implementing co-treatment models effectively requires careful planning, clear role definition, and ongoing communication between the collaborating professionals. Before initiating co-treatment, the BCBA and the collaborating professional should identify specific clinical goals that would benefit from an integrated approach. These goals should span both disciplines' areas of expertise and be difficult to address effectively through separate sessions alone. If the goals can be addressed equally well through independent sessions, the justification for co-treatment is weaker.

Session planning for co-treatment should specify each professional's role and responsibilities within the session. This includes determining who will lead specific activities, how transitions between activities will be managed, what data each professional will collect, and how decisions will be made during the session if the client's behavior requires modifications to the plan. Without clear role definition, co-treatment sessions risk becoming disorganized or dominated by one professional while the other observes passively.

Data collection during co-treatment sessions must be rigorous enough to support both clinical decision-making and billing documentation. Each professional should be collecting data relevant to their discipline-specific goals. The behavior analyst might collect data on response rates, prompt levels, and reinforcement delivery, while the speech-language pathologist collects data on communication modality use, language complexity, and pragmatic communication targets. This parallel data collection provides the evidence needed to demonstrate that both professionals are providing active, skilled services during the session.

The co-treatment model presents unique supervision challenges. BCBAs supervising RBTs who participate in co-treatment sessions must ensure that the RBT understands their role, can implement behavioral procedures while coordinating with the other professional, and can maintain data collection quality in the more complex co-treatment context. Supervision of co-treatment sessions should include observation of the coordinated service delivery, not just the behavioral components in isolation.

Client and family perspectives should inform co-treatment decisions. Some families prefer the efficiency of co-treatment sessions, which reduce the number of separate appointments they must attend. Others prefer separate sessions, which may allow for more focused attention on discipline-specific goals. The client's response to the co-treatment format should also be monitored, as some clients may find the presence of multiple professionals overwhelming or distracting.

Documentation of co-treatment sessions must clearly differentiate the services provided by each professional. Each professional should complete separate documentation that describes their specific contributions to the session, the data they collected, the clinical reasoning behind their interventions, and the outcomes observed. Documentation that merely describes shared activities without distinguishing each professional's unique contribution does not adequately support co-treatment billing.

Outcome monitoring should compare client progress during co-treatment periods to progress during separate treatment periods when possible. This comparison helps determine whether the co-treatment format is producing better outcomes, comparable outcomes with greater efficiency, or no additional benefit beyond what separate sessions would produce. If co-treatment is not producing measurable benefits, the ethical and clinical justification for continuing it is weakened.

Ethical Considerations

The ethical implications of co-treatment in ABA are extensive and require careful attention from behavior analysts at all levels of practice. Code 1.01 of the BACB Ethics Code (2022) requires truthfulness in all professional activities, which has direct application to how co-treatment sessions are documented and billed. The documentation for each professional must truthfully represent the services they provided, the skills they applied, and the outcomes they observed. Any documentation that exaggerates a professional's contribution to a co-treatment session or that describes services that were not actually provided violates this fundamental ethical requirement.

Code 1.10 addresses billing practices specifically, requiring that behavior analysts bill accurately for services rendered and do not misrepresent the nature of services provided. In the co-treatment context, this means that billing must reflect the actual services delivered by the behavior analyst, not simply the fact that the behavior analyst was present during a session where another professional provided the primary service. Each billed unit must be supported by evidence of active, skilled behavioral service delivery that represents the behavior analyst's unique professional contribution.

Code 2.10 requires behavior analysts to collaborate with other professionals who serve their clients. Co-treatment represents one of the most intensive forms of such collaboration, and the ethics code's encouragement of collaborative practice supports the clinical rationale for co-treatment models. However, the obligation to collaborate does not override the requirements for accurate billing, appropriate documentation, and practice within scope of competence. Collaboration for its own sake, without clear clinical justification, does not meet the ethical standard.

Code 1.05 regarding scope of competence is directly relevant to co-treatment models. During co-treatment sessions, the boundary between disciplines can become blurred. The behavior analyst must maintain clarity about which activities fall within their scope of competence and which belong to the other professional's domain. Implementing speech therapy techniques, for example, is not within the BCBA's scope of competence, even during a co-treatment session with a speech-language pathologist. Each professional must contribute from their area of expertise.

Code 2.01 requires that services provided be in the client's best interest. This means that co-treatment should be implemented only when it genuinely benefits the client, not when it primarily benefits the providers through increased billing or reduced scheduling demands. The decision to co-treat should be based on a clinical analysis of whether integrated service delivery would produce better outcomes for the specific client, not on organizational or financial considerations.

Code 3.11 requires accurate documentation of professional activities. In co-treatment settings, this documentation requirement takes on additional importance because each professional must clearly demonstrate their distinct contribution. Documentation that describes shared activities without differentiating each professional's role does not meet this standard. Each professional's notes should be able to stand alone as evidence of the skilled services they provided, independent of the other professional's documentation.

The ethical responsibility to maintain defensible billing practices extends beyond individual session documentation to organizational policies and procedures. Organizations that implement co-treatment models should have written policies defining the clinical criteria for co-treatment, the documentation requirements, the billing procedures, and the quality assurance processes for reviewing co-treatment services. These policies protect both the organization and its clinicians from ethical and legal exposure.

Assessment & Decision-Making

Deciding whether and when to implement co-treatment requires systematic clinical reasoning rather than blanket adoption or rejection of the model. The first step is identifying clients whose treatment goals span multiple disciplines in ways that would benefit from integrated service delivery. Clients who are working on communication goals that involve both language development and behavioral support, clients whose sensory processing needs directly affect their behavioral programming, and clients whose motor skill challenges impact their ability to participate in behavioral activities are all potential candidates for co-treatment.

For each potential co-treatment arrangement, evaluate whether the specific goals require simultaneous professional input. Some goals are more effectively addressed through coordinated but separate sessions, while others genuinely benefit from real-time collaboration. For example, teaching an AAC device user to request items may benefit from co-treatment where the SLP addresses the communication modality and the BCBA addresses the motivational and behavioral components simultaneously. In contrast, goals related to basic compliance or daily living skills may not require the simultaneous presence of another professional.

Before initiating co-treatment, establish clear parameters including the frequency of co-treatment sessions relative to individual sessions, the specific goals that will be addressed during co-treatment, each professional's role and responsibilities during sessions, data collection procedures for each professional, documentation standards and review processes, and billing procedures that comply with payer requirements.

Review the specific billing policies of each payer that covers the client's services. Some payers have explicit co-treatment policies, while others require prior authorization or have specific documentation requirements. Understanding these requirements before initiating co-treatment prevents billing complications and ensures that the organization can be compensated for the services provided.

Develop a monitoring plan that evaluates the effectiveness of co-treatment compared to alternative service delivery models. This plan should include outcome measures for the goals addressed during co-treatment, measures of efficiency such as rate of skill acquisition per session hour, client and family satisfaction data, documentation quality review, and periodic reassessment of whether co-treatment continues to be the most appropriate model for the client's current needs.

Create a decision tree or clinical decision-making protocol that guides clinicians through the process of determining when co-treatment is appropriate. This protocol should include criteria for initiating co-treatment, criteria for modifying the co-treatment arrangement, and criteria for transitioning back to separate services. Having a structured decision-making process ensures consistency across the organization and provides documentation of the clinical reasoning behind co-treatment decisions.

Regularly audit co-treatment documentation and billing to ensure compliance with ethical standards and payer requirements. Audit findings should be used to improve processes, provide training when needed, and make organizational-level decisions about the co-treatment program's effectiveness and sustainability.

What This Means for Your Practice

If you are considering co-treatment models, start with a clear clinical rationale. Identify specific clients and goals where integrated service delivery would produce measurably better outcomes than separate sessions. Do not adopt co-treatment as a general practice model without evaluating its appropriateness for each individual case.

Invest time in building strong collaborative relationships with the professionals you would co-treat with. Effective co-treatment requires mutual respect, clear communication, and shared understanding of each discipline's contributions. Meet with potential co-treatment partners before beginning sessions to discuss goals, roles, and expectations.

Develop rigorous documentation practices that clearly demonstrate your unique contribution to each co-treatment session. Your session notes should be able to stand alone as evidence of skilled behavioral services, independent of the other professional's documentation. If you cannot clearly articulate what you contributed to a session that the other professional could not have provided alone, the co-treatment arrangement may not be justified.

Stay informed about your payers' co-treatment policies. Billing errors related to co-treatment can trigger audits and recoupment demands that create significant financial and legal exposure. When in doubt about a payer's co-treatment policy, seek clarification in writing before initiating co-treatment billing.

Monitor outcomes to ensure that co-treatment is actually benefiting your clients. If the data do not demonstrate that co-treatment is producing better results than alternative service delivery models, be willing to modify or discontinue the co-treatment arrangement. The clinical justification must be ongoing, not just present at initiation.