Trends in US State and Territory Participation in Interstate Healthcare Licensure Compacts (2015-2024)

Interstate healthcare licensure portability is an increasingly critical issue facing healthcare in the US today.^1–3  Protecting the safety of its citizens is a critical role for individual state/territory-level clinician licensure groups, who must ensure patient safety by implementing certain requirements of all licensees practicing in the state and providing oversight of these licensees to protect the public from potential bad actors.⁴  Licensure groups effectively provide this oversight through the process of issuing and revoking state-level licenses.⁵  The process of licensing professionals at the US state/territory level has the benefit of states being able to tailor rules for practice to best meet the needs of its citizens and maintain state/territory sovereignty.⁶  However, this structure creates barriers to healthcare access in several ways.

For states with rural areas that may lack specialty care providers and/or face healthcare workforce shortages generally, acquiring a new, state-specific license can be a barrier to recruiting healthcare providers to meet this need.^7–12  Additionally, states with large patient populations who experience other barriers to healthcare access—such as a lack of transportation and low socioeconomic status—may be invested in attracting additional healthcare providers to facilitate healthcare access for underserved patients.^13,14  Healthcare licensure portability has also been an issue for any healthcare professionals moving across state lines for any reason, as employment for any state-issued licensee is predicated upon completing an additional licensure process in the new state of residence, which can be a time-intensive and costly process for the licensee and licensing bodies that process these applications.¹⁵  Interstate licensure also impacts the provision of telehealth services, which have the potential to lower costs to healthcare systems and patients,^16–21  as well as increase healthcare access for many patients residing in healthcare shortage areas.^21–23  Recent evidence suggests telehealth delivery allows rural patients to be served within their communities, and may be more cost-effective when serving a large number of patients from highly rural populations.^16,24  However, access to licensed healthcare providers for those patients who could benefit from telehealth remains a barrier to widespread adoption of telehealth services.⁷  More broadly, the COVID-19 public health emergency (PHE) in the US introduced unprecedented need for out-of-state healthcare providers to deliver healthcare during the PHE, further highlighting the need for change to traditional models of interstate healthcare licensure.^25,26 

Several strategies have been proposed and adopted as solutions to this problem. For example, state reciprocity agreements, such as those in Louisiana, allow a state medical board to issue a medical license without examination if the provider possesses “a valid, unrestricted license to practice medicine…in any other state of the US provided the board is satisfied that the license from the other state is based upon an examination and other requirements substantially equivalent to the requirements of this Part.”²⁷  However, while reciprocity agreements have been successful in certain cases—like an emergency licensure reciprocity program in New Jersey during the first year of the COVID-19 PHE²⁸ —such reciprocity agreements limit the ability of state licensing boards to protect the public from bad actors, as they do not inherently provide a mechanism for transparency and accountability if a provider later receives disciplinary action or restrictions to a license held in another state. Another strategy utilized to address this issue is reliance on federal authority, such as Veterans Affairs (VA), Indian Health Services, and the Department of Defense. For example, a VA Rule allows healthcare professionals within the VA “to deliver health care services in a State other than the health care professional's State of licensure, registration, certification, or other State requirement, thereby enhancing beneficiaries’ access to critical VA health care services”.²⁹  This process works well within the VA system but also does not provide a mechanism for transparency and accountability for non-VA providers, including VA contractors and VA providers working in the community, or for transmission of information from the VA to state boards regarding any non-VA practice.

In recent years, there have been several move-ments to improve and simplify the licensing process to improve cross-state practices for physicians, nurses, and other select healthcare providers through interstate healthcare compacts. According to the National Center for Interstate Compacts, “an interstate compact is a legally binding agreement between 2 or more states. Similar to a contract, a compact establishes a formal, legal relationship among states to address common problems or promote a common agenda.”³⁰  The first example of such a compact is the Nurse Licensure Compact (NLC). Established in 1999 by the National Council of State Boards of Nursing (NCSBN), the NLC allowed eligible nurses to practice nursing within any participating state.³¹  As of April 2024, several healthcare professions have identified, adapted, and adopted an interstate compact model as a strategy to address barriers to interstate practice. However, with many states still not participating in some if not all healthcare interstate licensing compacts, licensure portability remains a barrier to healthcare practice for many specialties, areas, and services. For example, healthcare systems are facing staff shortages, such as a shortage of licensed nurses.^32,33  Additionally, while the number of licensed physicians has been increasing, so has the mean age of licensed physicians, and the number of physicians failing to renew their licenses is outpacing the number of physicians receiving their first licenses.^12,34,35  These issues were exacerbated during the first years of the COVID-19 PHE, when telehealth services were increasingly critical, not only for the triage of patients, but for other healthcare service delivery to reduce the spread of the COVID-19 virus.^36,37  As telehealth utilization surged, licensure portability also persisted as a barrier to telehealth utilization across many healthcare disciplines,^38–40  both from the perspective of healthcare providers and licensing professionals.⁴¹  Not only were historic numbers of patients seeking care, but healthcare staff shortages due to COVID-19 infection and death also highlighted the need for interstate portability of healthcare licensure.^42,43  In response to this crisis, the federal government issued waivers and provided guidance to healthcare providers and Federally Qualified Health Centers with the aim of reducing some of these barriers to interstate practice.^44,45  However, many of these waivers were temporary, and many have already expired. Thus, as we move beyond the COVID-19 PHE, the need for a long-term mechanism to address barriers to interstate healthcare practice is more apparent now than ever before.

Although previous work has documented the implementation history and challenges of individual interstate healthcare compacts, such as the NLC³¹  and the Interstate Medical Licensure Compact (IMLC),^46,47  these studies have described the process of compact implementation within specific health professions. Although no two interstate compacts are identical, each meeting the needs of key stakeholders within the profession, this individualized approach does not fully describe how interstate compacts are generally received by state legislative bodies, whose perspectives and voting behavior may shift as they become aware of additional interstate healthcare compacts over time and are exposed to more compact legislation. One prior policy perspective article has documented several key milestones for 10 healthcare compacts, but did not examine interstate compact bill passage by states over time.⁴⁸  To our knowledge, our study is the first to provide a comprehensive review of key compact milestones and healthcare compact bill passage by states over time for all active interstate healthcare compacts. This descriptive analysis fills a gap in the literature by examining interstate healthcare compact processes and timelines across all healthcare professions pursuing a compact process. By examining key dates and metrics for all interstate healthcare compacts in the current study, we aim to shed light on the legislative climate for such compacts across time to inform future efforts for interstate compact implementation and interstate licensure portability broadly across all healthcare professions.

This study aimed to describe the landscape of interstate healthcare compacts in the US by examining state and territory participation in interstate healthcare compacts over time.

We systematically examined the state of licensure portability by analyzing state/territory interstate healthcare compact participation information from interstate healthcare compact websites, individual state/territory legislative websites, the LegiScan website,⁴⁹  and the Center for Connected Healthy Policy's website.⁵⁰  This study was conducted as part of a larger program evaluation of an interstate healthcare licensure compact program and was determined not human subjects research by the University of Arkansas for Medical Sciences Institutional Review Board (262474).

To identify key milestones in interstate healthcare compact implementation over time, we first reviewed published articles,^31,46,51  individual compact websites, and information provided by the Council of State Governments (CSG) from the National Center for Interstate Compacts.⁵²  CSG facilitates, supports, and monitors interstate compacts for many professions (not just healthcare). We then identified common data elements that measure these key milestones to extract for our analysis. Interstate compacts are dependent on individual US states and territories passing legislation with identical language within the legislative bodies of the individual states/territories. Thus, finalizing model legislation is a common and critical compact milestone across all interstate compacts. Once model legislation is finalized, compact champions in individual states and territories must then work to introduce the model legislation to the legislative bodies within their states/territories as bills, and have that legislation successfully advance through all stages to become state or territory law. For this study, we examined only legislation specific to interstate compact participation and not legislation intended to address barriers to interstate practice through other mechanisms (such as state reciprocity agreements or other agreements made between specific individual states external to interstate compact participation). All compacts we examined also set a number of participating states/territories that must have passed the model legislation in order to activate compact operations. Thus, the final set of variables included: date of first compact discussions, date compact model legislation finalized, number of enacted states required for operation, year first state enacted compact legislation, and year compact became operational.

To examine interstate healthcare compact bill passage over time, we identified the date the legislation was signed by the governor (or similar role) or the date of announcement or notification that the bill was signed into law as the most appropriate standard data element to represent state-level compact participation to include for analysis. This date is common to all US states and territories despite variation in legislative processes and remains key for all interstate healthcare compacts; however, many compacts require additional steps and processes before eligible healthcare professionals practicing in a new member state can practice under compact rules, such as states with legislation passed but with partial or delayed/awaiting implementation, member states with legislation that did not issue licenses through the compact, states with enacted legislation but practice was not yet permitted, and states with enacted legislation but not yet issuing or accepting compact privileges.

At the beginning of the study in August 2021, CCHP tracked state legislative actions regarding 6 interstate healthcare compacts: NLC,⁵³  IMLC,⁵⁴  the Psychology Interjurisdictional Compact (PSYPACT),⁵⁵  the Physical Therapy Compact (PTC),⁵⁶  the Emergency Medical Services Compact (EMSC),⁵⁷  and the Audiology and Speech-Language Pathology Interstate Compact (ASLP-IC).⁵⁸  Ten additional healthcare compacts were identified through qualitative interviews (conducted as part of a program evaluation) with interstate compact staff and other stakeholders, web searches, and information from the Council of State Governments from the National Center for Interstate Compacts:⁵²  the Occupational Therapy Licensure Compact (OTLC),⁵⁹  the Advanced Practice Registered Nurse Compact (APRNC),⁶⁰  the Counseling Compact (CC),⁶¹  the Physician Assistant Licensure Compact (PALC),⁶²  the Dentist and Dental Hygienist Compact (DDHC),⁶³  the Interstate Massage Compact (IMPact),⁶⁴  the Social Work Licensure Compact (SWLC),⁶⁵  the Dietitian Licensure Compact (DLC),⁶⁶  the Interstate Compact for School Psychologists (ICSP),⁶⁷  and the Respiratory Therapy Licensure Compact (RTLC).⁶⁸  However, the RTLC was not far enough along in the compact development process (ie, a draft of model legislation was currently under public stakeholder review at the time of the study) to be included in our analyses and was thus excluded. Two additional interstate compacts were identified but determined by the study team as not serving healthcare professions (the Cosmetology Licensure Compact [CLC]⁶⁹  and the Interstate Teacher Mobility Compact [ITMC]).⁷⁰  Finally, the National Association of Boards of Pharmacy was identified as having examined the feasibility of creating healthcare compact for pharmacists but, to date, has not yet taken any additional steps toward compact implementation.⁷¹  This yielded a total of 15 healthcare licensure compacts included for analysis. A full list of the identified interstate compacts can be found in Table 1.

One researcher visited each of the websites for the 15 active healthcare compacts, documented state/territory-level compact participation states and dates (if available), and verified this information using state/territory-specific legislative websites and/or LegiScan. States/territories were coded as participating in a compact if state/territory legislation had been signed into law by the governor (or similar role).

Key milestone data elements in interstate healthcare compact implementation over time were extracted and recorded in Microsoft Excel (version 2406; Microsoft, Redmond, Washington). Analysis of state-level participation in interstate healthcare compacts from legislative websites was conducted in Microsoft Excel and R (version 4.3.2; R Core Team, Vienna, Austria)/RStudio (version 2023.9.1.494; Posit team, Boston, Massachusetts).^72,73  A choropleth map of state-level participation across all interstate healthcare compacts was created using ArcGIS Pro (version 3.1.2; Esri, Redlands, California).

A summary of healthcare compact development can be found in Table 2 and 3. A full list of all dates of compact legislation passed for each of the 15 identified healthcare compacts as of April 2024 can be found in the Appendix.

Of the 15 active interstate healthcare compacts identified, all 15 compacts saw the first state/territory pass compact-specific legislation in at least 1 state/territory in the year following or the same year of the approval of the drafted model legislation. However, the time between when compacts were first discussed to the approval of the drafted model legislation varied considerably between compacts, ranging from 20 years (APRNC) to 1 year (EMSC, OTLC, DLC, and CC). Unlike other healthcare compacts, both the NLC and the APRNC have had 2 iterations. The original NLC became operational in 2000, and the enhanced NLC, which had finalized model legislation in 2015, became operational in 2018.¹¹⁵  The transition from the original to the enhanced NLC required new state legislation or legislative amendments to be introduced in all 25 existing member states, beginning in 2016. The APRNC similarly had 2 iterations. The original APRNC finalized model legislation in 2002 and had 3 states pass this legislation between 2004 and 2007.³¹  However, like the enhanced NLC, a revised APRNC model (initially called the Consensus Model for APRN Regulation, but now just referred to as APRNC) was drafted in response to feedback from stakeholders on the need to make changes to increase adoption in non-participating states. State-level participation for these newer iterations of these 2 compacts are reported in Table 2 and 3.

Between 2015 and April 2024, the most active years for state passage of interstate compact legislation were 2022 (50 bills/amendments), 2021 (46 bills/amendments), and 2023 (44 bills/amendments). To visualize the passage of bills over time by each of the active interstate healthcare compacts, we have plotted the cumulative number of bills passed by compact between January 2015 and April 2024 (see Figure 1).

The frequency of states/territories currently participating in 0 through 11 interstate healthcare compacts can be found in Table 4.

Among the 15 healthcare compacts identified, the number of states and territories participating in healthcare compacts ranged from 0 compacts (6 states/territories: Alaska, California, Massachusetts, New York, American Samoa, and Puerto Rico) to 11 compacts (2 states: Nebraska and Utah). Eight states were participating in 8 healthcare compacts, the most common number of healthcare compacts among states/territories.

To examine whether states pass multiple compact bills in quick succession or more slowly over time, we plotted a histogram of the number of bills passed in each state/territory between 2015 and 2024 (note that 2024 is a partial year, with statuses recorded as of April 2024; see Figure 2).

As shown in Figure 2, few states and territories pass more than 2 healthcare compact-related bills in any year. The most bills passed in a single year by any state/territory was Ohio in 2021, which passed 6 healthcare compact-related bills that year. A histogram of the number of healthcare compact-related bills passed by each state/territory in all years between 2015 and 2024 can be seen in Figure 3.

As can be seen in Figure 3, in all years, the most common number of compact-related bills passed by states is 1. The most active year for healthcare compact bills overall was 2022, when 4 states passed 3 compact-related bills (Delaware, Indiana, Tennessee, and Utah), and the second most active year was 2021 when Ohio passed 6 healthcare compact-related bills, Maryland passed 4, and 3 additional states passed 3 (Alabama, Georgia, and Kansas). However, 2021 was also the most active year for states passing a single healthcare compact-related bill when 17 individual states/territories passed only 1 compact bill. In 2023, the third most active year for healthcare compact legislation passage on record, 2 states passed 4 healthcare compact-related bills (Vermont and Washington), and 4 states passed 3 healthcare compact-related bills (Arkansas, Missouri, Montana, and Wisconsin).

A US map depicting the total number of enacted interstate healthcare compact bills in each state/territory as of April 2024, is shown in Figure 4.

Since the beginning of the NLC in 1994,³¹  interest in the development of interstate healthcare compacts has grown to include 15 separate, active healthcare compacts, with 291 individual state compact participation bills passed as of April 2024. In the last decade, the landscape of interstate healthcare practice has changed dramatically, which has the potential to increase healthcare access for patients and facilitate mobility for healthcare providers. Our study is the first to our knowledge to systematically examine the passage of state bills for interstate compact participation across all healthcare professions over time.

In this study, we examined state and territory participation in interstate healthcare compacts by identifying all state/territory healthcare compact bills signed into law between 2015 and April 2024 and reporting trends observed across states, time, and individual compacts. In general, we found that states and territories have increased the number of healthcare compact-related bills they have passed over time, which has increased the number of providers eligible to practice under compact jurisdiction and thus increased the potential for licensure portability for healthcare professionals. Our study validates a recent finding that interstate healthcare compact participation has increased in recent years.⁴⁸  We found the most active years for state/territory compact bill passage were 2022 and 2021, which were the first 2 full years of legislative sessions following the declaration of the COVID-19 PHE. However, despite this recent increase in the number of bills passed by states, our analysis of compact legislation revealed that individual states and territories rarely passed more than 1 or 2 healthcare compact bills in a single year (see Figure 2), demonstrating that it is not generally the case that a larger number of compact bills are passed in quick succession following the passage of a first healthcare compact-related bill in that state/territory. It seems likely that the overall increase in the number of compact bills passed in states and territories, as well as the large number of healthcare compact bills passed in a few states (eg, Ohio), could be related to the circumstances created by the PHE. Future research is needed to examine the impact on interstate practice these changes have had, such as an examination of the number of practicing healthcare professionals within states that enter into interstate compact membership, and a more recent analysis¹¹⁶  of the number of disciplinary actions taken by occupational licensing boards immediately following compact membership.

A few recent examples suggest that this trend may be changing. For instance, although none of the bills have passed as of this writing, New York—a state that is not currently a member of any interstate healthcare compact—introduced compact-related bills for 9 healthcare compacts across the 2023-2024 legislative sessions (IMLC, PSYPACT, NLC, PTC, ASLP-IC, OTLC, CC, PALC, and IMPact). Additionally, although the majority of bills retrieved during our study were specific to each individual compact (following drafted model legislation as produced by individual compacts), several states have introduced and/or passed legislation pertaining to multiple interstate compacts in 1 bill. Four of the 9 compacts in session as of this writing in New York legislative bodies are all pending from a single bill (2023-S6883): PSYPACT, PTC, ASLP-IC, and CC.¹¹⁷  The Oregon House of Representative is also reviewing a single bill as of this writing (HB4071) that, if passed, would enter Oregon as a member of both the CC and the SWLC.¹¹⁸  However, it is unknown if these multi-compact efforts will be successful, although this strategy has been successful at least once: Missouri's Senate Bill 70 was signed into law in July 2023 and entered into membership with IMLC, CC, and SWLC.¹¹⁹  Although these recent examples could mark the beginnings of a shift in state approaches to interstate healthcare compact membership, we do not yet have evidence that introducing bills for a large number of healthcare compacts in a single year is common practice for any state or territory. However, not all interstate healthcare compacts operate in the same way, as compacts typically determine their rules based on input from multiple stakeholders to best fit the needs of the profession,¹²⁰  but others have argued that some interstate compact models better address the barriers to healthcare licensure portability than others.¹²¹  It is too early to evaluate the effectiveness of multi-compact bills on healthcare access and interstate healthcare licensure, but it remains an important question for future researchers. Relatedly, the effect of increased interstate healthcare compact participation amongst US states and territories may not be identical for all healthcare professions and is also worthy of future study.

Our examination of interstate healthcare compact bill passage by specific healthcare compacts (see Figure 1) revealed several trends but also patterns specific to individual compacts and healthcare professions. First, for nearly all compacts first discussed more than 5 years ago (ie, prior to 2019), we observed patterns of compact-related legislation passed by many states/territories around the same time, as well as plateaus of legislative activity when few states/territories successfully passed compact-related legislation. Although this is certainly influenced by the timing of legislative sessions, several compacts (ie, NLC, IMLC, PTC) experience more rapid adoption by states/territories earlier in compact implementation, and later implementation is characterized by states/territories passing compact legislation more slowly. This aligns with prior work documenting a stall in compact growth characterized by participation of new states/territories (however, recall that the rapid adoption of the NLC between 2016 and 2018 included adoption of the enhanced NLC by states/territories that had previously participated in the original NLC, which likely facilitated expeditious passage of this modified legislation).³¹  As the map in Figure 4 illustrates, some states/territories are particularly receptive to compact participation and may more readily pass new interstate healthcare compact legislation than others. One exception to this trend is the APRNC, which changed its model legislation in an effort to address profession-specific barriers to implementation and has not yet experienced rapid adoption. PSYPACT also demonstrated a unique pattern of more gradual initial adoption and a more recent (during the COVID-19 PHE) period of rapid adoption. PSYPACT has a unique model among the interstate healthcare compacts we examined, in that the scope of practice for PSYPACT providers is limited to telehealth. This may have presented unique barriers and facilitators to adoption (ie, an understanding of the need for tele-mental health services during the COVID-19 PHE). Additionally, the EMSC has shown more gradual state/territory adoption over time without periods of rapid adoption. However, EMS providers are a unique profession among the 15 interstate healthcare compacts we examined; namely, many EMS providers are volunteers, presenting a different fiscal equation for both the providers themselves and the state/territories who license them. Several other more recently established compacts such as the ASLP-IC, CC, OTLC, PALC, and SWLC appear to be exhibiting the initial rapid adoption phase of compact implementation, but the establishment of these compacts is still too recent to observe trends in interstate healthcare compact state/territory bill passage. One hypothesis is that the education and effort of the first interstate healthcare compacts may have paved the way for more rapid adoption for later compacts who may not experience the same plateaus in state/territory participation. However, it is still too early in interstate healthcare compact history to examine this possibility.

As an exploratory study, our results cannot speak directly to what influences caused bills to be passed at certain times and not others. Future studies and more time passing following the end of the PHE may be able to shed additional light on the drivers of these legislative actions. However, the COVID-19 PHE likely influenced licensure portability and compact implementation in multiple ways. Our analysis of state compact bill passage supported this view, demonstrating that 2022 and 2021 were the most active legislative years in healthcare compact history (50 and 46 healthcare compact bills passed by states, respectively), with the most recent completed year (2023) also demonstrating significant legislative activity (44 healthcare compact bills passed). Others have suggested that the COVID-19 PHE underscored the need for changes to traditional occupational licensure.²⁶  In further support of this finding, the American Medical Association, the Uniform Law Commission, and the Federation of State Medical Boards (FSMB) have all released final model legislation for a Model Telehealth Act in response to specific challenges to telehealth practice encountered during the COVID-19 PHE, with the intention of facilitating passage of state laws to enable interstate telehealth practice.¹²²  Future work is needed to evaluate the effectiveness of these legislative changes on interstate licensure portability, healthcare licensure mobility for healthcare professionals, and increased healthcare access for patients.

This study should be interpreted with several limitations in mind. First, although our analysis of interstate healthcare compact-related bills passed in all US states and territories is comprehensive to the best of our knowledge, our findings cannot directly point to underlying mechanisms for these changes. Although we observed increases in the number of state compact bills passed in recent years, we can only speculate that the timing of these increases may be related to challenges introduced by the COVID-19 PHE, but we cannot determine this for certain. Future work will need to be conducted to identify the cause of these changes. Additionally, our study was limited to interstate healthcare compact state bills that were signed into law and did not include bills proposed that did not get signed into law. Although our approach allowed us to identify some recent, multi-compact, single bill efforts from a few states, a different approach would be needed to systematically investigate how many different proposed bills and types of bills (single or multi-compact) were introduced in each state before becoming a compact member. Additional analysis is needed to identify whether multiple bills proposed over multiple legislative sessions are typically necessary for ultimate success with state healthcare compact legislation, or if this is a problem specific to certain states/territories, time periods, or compacts.

The landscape of interstate healthcare practice has changed dramatically in the last decade, and state/ territory participation in interstate healthcare licensure compacts has expanded over time. We aimed to examine the history and current landscape of the interstate compact model as a promising tool to address licensure portability problems for healthcare providers in an increasingly mobile society. We found that state/territory passage of interstate healthcare compact bills has been most active in the most recent complete years of analysis, and that there is wide variation in state/territory-level participation across the 15 interstate healthcare compacts we examined, ranging from states/territories participating in 0 to 11 compacts. We also found that many compacts experience an early period of rapid adoption of compact legislation by many states/territories, but that this varies considerably between professions with different challenges and compacts with different models.