Private Practice, Private Insurance, and Private Pay Mental Health Services: An Understudied Area in Implementation Science

Abstract

The private practice setting is understudied. Private practice includes settings in which mental health providers are unaffiliated with healthcare and hospital systems. Private practices may accept insurance (private and sometimes public) or no insurance (private pay). Increasing attention to this setting is critical to facilitating equitable access to mental health services, especially given enduring mental health workforce shortages and service waitlists. Further, there have been recent federal government calls to increase mental health and physical healthcare parity and to reduce out-of-pocket patient costs. Implementation science theories, models, frameworks, and methods can help illuminate determinants of private practice service availability and quality (e.g., evidence-based intervention delivery with fidelity), guide evaluation of implementation outcomes such as cost and acceptability of interventions to patients, and identify strategies to mitigate barriers to high-quality, affordable private practice services. This article suggests research questions to begin filling the private practice research gap using an implementation determinants framework— the Consolidated Framework for Implementation Research (CFIR) 2.0. Research questions are proposed across CFIR domains: outer context (e.g., policies impacting whether private practices accept insurance); individuals involved (e.g., provider professional experiences; direct-to-consumer marketing impacts on evidence-based intervention demand); innovation characteristics (e.g., appropriateness for private practice); inner context (e.g., organizational characteristics); and implementation processes (e.g., innovation sustainability). The illustrative research questions aim to begin a conversation amongst researchers and funders. Bringing an implementation science lens to the private practice context has the potential to improve the quality and affordability of mental health care for many.

Implementation science aims to improve the uptake of evidence-based practices in usual care. To date, implementation research has primarily focused on hospital, school, and community settings as contexts, with little research explicitly focused on private practice settings (Frank et al., 2022; Milgram et al 2022; Stewart & Chambless, 2007). However, approximately half of mental health outpatient providers in the United States work in a private practice setting (Lin et al., 2022; Harrington, 2013). Private practice includes settings in which mental health providers are unaffiliated with healthcare and hospital systems. Private practitioners may be in a solo or group practice and may accept a range of insurance types (private and sometimes public) or no insurance (private pay). We argue for increased research on private practice due to: (1) the dearth of focused implementation research in private practice settings; (2) the number of mental health providers delivering care in this setting; and (3) recent calls by the Biden administration to increase mental health parity due to high out-of-pocket costs and low access to mental health for those seeking care (The White House, 2023).

In this article, we highlight the importance of identifying contextual determinants of private practices and employing implementation strategies within private practice settings to increase clinician use of and client access to evidence-based interventions (EBIs). We use the updated Consolidated Framework for Implementation Research (CFIR 2.0; Damschroder et al., 2022) to organize potential implementation research questions (Table 1). Below, we elaborate on exemplar research questions using the CFIR 2.0 framework, which includes five domains: outer setting (setting(s) influencing the private practice), individuals involved (roles and characteristics of practice management, providers, clients), innovation factors (the EBIs), inner setting (the private practice’s organizational environment), and the implementation process (activities and strategies to increase EBI use). Our proposed research questions aim to extend existing research to understand how private practices are both similar and different to other practice settings. This research agenda stands to increase EBI access and quality for the numerous clients who access mental health services through private practices.

Table 1.

Private Practice Research Questions by CFIR 2.0 Domain

CFIR 2.0 Domain	Example Research Questions
Outer setting	How do payment thresholds affect the proportion of providers willing to accept private insurance? Which incentives are most effective in encouraging providers to remain in private insurance networks? What reimbursement thresholds are sufficient to encourage private pay providers to deliver EBIs? How do insurance company mandates and state or federal legislation designed to increase EBI delivery affect provider behavior? How do these mandates change consumer demand for EBIs? What incentivizes private insurance companies to pay for EBI training and reimbursement for providers (e.g., federal or state policy mandates, social pressure, expenditure forecasts)? What strategies can private practice providers leverage to obtain sustainable sources of funding for EBI training and delivery? What policies and/or who could most effectively prompt state accreditation agencies to pass policies that promote the use of EBIs (e.g., through continuing education requirements)? To what extent does client demand influence clinician delivery of EBIs, especially in an unregulated context such as private pay? To what extent do policy and social drivers (e.g., structural social determinants of health, cultural norms) explain mental health services access. For example, how does geographic variability relate to the number of private practice clinicians? How do Big P and little p insurance policies drive individuals to private practice settings (e.g., through pathways such as generating narratives around who should or should not benefit from certain types of insurance coverage and delineating which levels of coverage and subsidies are acceptable)? Which state, federal, or professional policies might be created or more effectively leveraged to make out-of-pocket costs comparable for individuals seeking care from clinicians accepting private pay versus public or private insurance? Which policy components are most critical to increase the likelihood of positive policy impacts on the affordability and accessibility of EBIs to individuals with and without insurance? Which policy and social factors (e.g., reimbursement, social pressure, mandatory guidelines) encourage provider uptake of public and private insurance so that more individuals can receive in-network, evidence-based care?
Individuals involved	What proportion of providers who only accept private pay were initially trained in a public system (e.g., community mental health initiatives) before moving to private pay? What proportion of these trained clinicians remain in the public sector? At what rate do clinicians who enter private practice continue to offer EBIs? How does length of time in treatment for individuals who access private pay compare to those with private or public insurance, and how does this rate vary by fidelity of EBI care received? How do requirements for client eligibility vary between private practice versus community mental health/hospital providers (e.g., insurance accepted, types of clients seen, requirements for clients to have a primary care doctor in their system)? To what extent do service access (proportion, timeliness) and quality outcomes differ by sociodemographic and cultural characteristics among clients served by private practitioners? How do these differences compare to clients receiving public insurance/private pay? What are private practice providers’ perceptions of clientele eligible for EBIs versus other types of care? How might these perceptions inhibit or promote motivation to deliver EBIs? How do client treatment outcomes compare for those receiving care from providers who accept public insurance, private insurance, or private pay for the client’s care? Are providers who offer EBIs more or less likely to only accept private pay? If so, which implementation strategies might best be leveraged to increase equitable access to EBIs for clients who cannot afford private pay? Which actors (e.g., regulatory agencies, legislators) are best poised to be involved in such strategies? Who are the key intervention deliverers, administrators (e.g., mid- and high-level leaders), and implementation team members who might be involved in private practice settings? Are methods for identifying these implementation actors different compared to other health care delivery settings? What proportion of private practice clients receive EBIs? What motivates private practitioners to obtain EBI certification/training?
Innovation factors	To what extent do EBIs fit the needs (i.e., appropriateness) and preferences (i.e., acceptability) of clients presenting in a private practice setting, as perceived by both providers and clients? To what extent do private practice providers perceive EBIs as being feasible and acceptable to deliver in this setting? Which EBI characteristics are most acceptable to private practice providers, and which require the most tailoring or adaptation to the private practice context? To what extent does the perceived appropriateness of EBIs impact the rate or quality (i.e., fidelity) of EBI delivery in private practice settings, and how do treatment outcomes vary by population subgroup? Is the innovation affordable for the private pay provider to be trained in and sustain accreditation and/or fidelity? Is the EBI feasible to integrate into the private practice workflow (e.g., among solo private practitioners)?
Inner setting	How does EBI uptake (e.g., EBI type, proportion of services delivered) vary by organizational type (e.g., group vs. solo private practice)? What proportion of private practice providers offer EBIs? How does this rate vary based on whether the provider accepts insurance? How and why do they select which EBIs they deliver, if any? How does length of time on waitlists vary for clients seeking services from practitioners who accept private insurance only or private pay compared to those seeking services from public insurance providers? Which inner setting factors (e.g., provider credentials, client engagement strategies) most impact waitlist length? How does implementation resource capacity (e.g., funding, information technology) differ in private practice settings? What organizational norms and cultural aspects (e.g., client-centeredness) facilitate EBI delivery in private practice, and what are key ways in which these norms and cultural aspects differ from other healthcare settings? Which setting characteristics require the most modification to accommodate EBI delivery with fidelity?
Implementation process	How can implementers recruit private practitioners into trainings focused on EBIs? How do private practitioners select which EBIs to deliver? Which implementation activities and phases (e.g., pre-implementation, implementation, sustainment) are most often supported through funding made available through Big P policy (e.g., Centers for Medicare and Medicaid Services) compared to private, little p policy (e.g., foundation grants, institutional overhead)? How does implementation process fidelity (duration, proportion of key activities completed; Alley et al., 2023) differ among private practice providers relative to providers in hospitals or publicly funded community mental health clinics? Which methods for selecting and tailoring implementation strategies are best suited to private practice settings? To what extent could inter-organizational private practice networks be leveraged to increase motivation and capacity to deliver EBIs? To what extent do providers who accept private insurance adhere to EBI delivery as intended (i.e., fidelity)? How can EBI fidelity be feasibly and effectively monitored among private practice providers?

Note. EBI = evidence-based intervention

Given our focus on potential research questions to spur private practice mental health service research, our primary audience includes implementation science and health services researchers. However, there are two critical additional audiences: grant funders and policy actors (e.g., legislators, administrative policy officials, licensing boards, insurance companies). Grant funders’ priorities shape data collection efforts and provide resources for necessary data infrastructure expansions. Policy actors (Cruden et al., 2023) also develop and enforce policies that shape which data are collected, how key outcomes are determined (e.g., through quality monitoring guidelines), and how/when data are shared. Federal policy actors, such as Congress and administrative policy officials within the Centers for Medicare & Medicaid Services, are also poised to define who can serve as or be served by a private practice provider and how private practice can be monitored, evaluated, and funded (Hinton et al., 2022).

Within the outer setting, private practices may vary in the extent to which they are subject to both little p (e.g., departmental-, organization-, or system-level policies) and Big P (state and federal laws) policies. Prior health services research in the United States has focused extensively on the impact of Big P policies such as the Mental Health Parity and Addiction Equity Act of 2008 (MHPAEA), insurance coverage, service utilization, and out-of-pocket costs. Yet, this work has primarily examined impacts among privately-insured (not private pay) clients, and has largely concluded that true parity of mental health and physical healthcare has not been reached (Gertner, Rotter, & Cruden 2018; Harwood et al., 2017). Furthermore, MHPAEA did not apply to payment rates set by private pay providers (Harwood et al., 2017). Even with public or private health insurance, the minority of children and adults with mental health concerns receive access to mental health services, and even fewer receive evidence-based services. Barriers to accessing services include long waitlists due to provider shortages and difficulty finding providers who accept insurance (Andrade et al., 2016). Some clients turn to private practice in search of specialized treatment and shorter waitlists even if it means incurring higher out-of-pocket costs.

Beyond Big P policies such as MHPAEA, which have variable impacts on private practitioners, there are little p policies that are relevant to private practice settings that have not been extensively examined. For instance, insurance reimbursement rates tend to be lower than market rates charged by private practice clinicians. Changes to insurance reimbursement rates are likely to impact the network of providers who accept insurance, which in turn might affect clients’ out-of-pocket costs. However, this has not been examined empirically. Other financial implementation strategies, such as enhanced reimbursement rates for EBIs, may also encourage EBI use in private practices. Beyond cost considerations, research has indicated that private practice providers are often incentivized not to take health insurance due to administrative burdens such as getting paneled, managing billing, and experiencing reimbursement delays (Frank et al., 2023; Hamp et al., 2016). Aside from insurers, policies set by regulatory bodies could also impact the cost and quality of private practice services. For instance, licensed mental health clinicians must maintain licensure through licensing boards, which typically require ongoing continuing education. Although licensing boards often maintain limited oversight regarding the quality of continuing education courses attended and services delivered by licensed providers, increasing this oversight may be an area for future intervention. Finally, the outer setting also includes factors such as social determinants of health and private practice culture. For example, research could explore how private practice norms and policies vary by geographical areas, and how historical and current housing segregation policies and practices impact where and how private practice providers operate.

At the level of individuals involved, direct-to-consumer marketing (Becker, 2015) focused on EBIs may influence which EBI trainings private practice clinicians seek to meet client demand. However, the extent to which direct-to-consumer marketing campaigns affect private practice clinicians’ behavior has not empirically been examined. Of note, there is evidence suggesting that clinicians working exclusively in private practice settings are willing to spend more time and money to learn new therapy approaches compared to clinicians working in other settings (Powell et al., 2013). This suggests that there are opportunities to leverage those resources to increase EBI use in private practice settings. Other determinants of EBI delivery in private practice settings include clinicians’ unique characteristics such as credentials, theoretical orientation, attitudes towards EBIs, and demographics (Beidas & Kendall 2010).

Importantly, there is likely to be variability in the acceptability (and thus availability) of EBIs in private practice settings depending on innovation characteristics such as intervention complexity (e.g., dialectical behavioral therapy may be less feasible to deliver as a solo practitioner than cognitive therapy) and intervention adaptability to the private practice context. There may also be value in implementation efforts that address private practice clinicians’ attitudes about EBI acceptability and appropriateness given research indicating that EBIs are perceived by some private practice clinicians as overly structured and not suitable to many clients (Milgram et al., 2023). In general, providers working in private practice settings are subject to fewer external pressures to adopt specific interventions than those in community-based public agencies (Hyzak et al. 2023). There are opportunities to capitalize on intervention, client, and clinician characteristics that might persuade clinicians to adopt EBIs.

Inner setting constructs such as organizational culture and climate have also been rarely examined in the private practice context yet are relevant. For example, organizational structures (e.g., group vs. solo practices) may impact EBI uptake and decisions to accept insurance (Frank et al., 2022). Anecdotal and scientific evidence (Beidas et al. 2012; Okamura et al 2018) suggest that many private practice providers were initially trained in systems that accept public insurance (hospitals, schools, or community mental health). Yet, clinicians who move into private practice settings may encounter organizational (little p) policies and cultural norms that encourage or discourage EBI use (Frank et al., 2022). Additionally, research examining relationships between EBI use and fidelity, provider cost, and waitlist length could elucidate whether EBIs are currently accessible to most clients.

Finally, it will be important to understand how the implementation process differs in private practice settings, especially when considering sustainability. Prior work has found that private practice settings have less capacity for sustainability than community hospitals and academic medical centers (Malone et al., 2021), highlighting the need to proactively plan for sustainment after successful EBI implementation. For instance, private practitioners in solo practice settings may face barriers to adopting and sustaining the use of EBIs after initial training given limited opportunities for consultation with other clinicians (Frank et al., 2022). Implementation strategies that support the development of peer consultation groups and that increase recognition of providers trained in EBIs may promote sustained EBI use. Additional strategies may be needed to recruit private practice providers to EBI-focused trainings, especially when those EBIs are perceived as not aligning with their theoretical orientation (Powell et al., 2013). Focused efforts to increase the reach of EBI training among private practice providers may improve the overall quality of client care in private practice settings.

We recognize that the lack of research in private practice may be due to challenges in conducting research in this setting. For one, there is a dearth of data. Insurance claims data do not include services obtained by uninsured clients or by insured clients who do not seek reimbursement for out-of-network services due to cost — two groups that comprise most private practice services. Lack of electronic medical record standardization also limits the potential of administrative data to better understand the private practice context. Further, insurance companies may be hesitant to disclose reimbursement rates because these rates are negotiated, rather than standardized. To provide more universal rate estimates and limit cost impacts on clients, policymakers could place caps on out-of-network costs (Duffy, Whaley, & White, 2020) and standardize rates relative to context (e.g., geography, case severity; Regier 2007). Additionally, the relatively smaller number of providers in each unit of private practice (compared to hospitals, for example) poses challenges to recruiting sufficient participant samples for typical causal inference analyses.

Fortunately, implementation science offers frameworks and methods for holistically identifying and addressing multi-level barriers to implementation in private practice settings. Examples include CFIR 2.0 (Damschroder et al., 2022), implementation mapping (Fernandez et al., 2019), standardized technical assistance reports (Thomas et al., 2022), context assessment tools (Robinson & Damschroder, 2023), adapted stepped-wedge or cluster randomized designs (Brown et al., 2017), and rapid qualitative analysis (Nevedal et al., 2021; Hamilton & Finley, 2020; Johnson & Vindrola-Padros, 2017). Additionally, policy actors and private practice provider partnerships could foster co-designed policies (Almquist, Walker, Purtle, 2023) and implementation efforts that improve access to and care quality in private practice settings.

Bringing an implementation science lens to the private practice context has the potential to improve the quality of mental health care for many, as individuals with public, private, or no insurance have cause to seek private practice care.