Interstate Medical Licensure Compact (IMLC): SPL Nexus, Eligibility, and Process

The Interstate Medical Licensure Compact (IMLC) is a binding statutory agreement enacted by participating U.S. state legislatures, territories, and the District of Columbia that establishes an expedited pathway for qualified physicians (MDs and DOs) to obtain full medical licenses across multiple jurisdictions. Developed with the support of the Federation of State Medical Boards (FSMB) and administered by the Interstate Medical Licensure Compact Commission (IMLCC), the Compact addresses multi-state licensure bottlenecks in cross-border specialty care, multi-site clinical networks, and decentralized clinical trials.

What Is the Interstate Medical Licensure Compact?

Under U.S. state medical practice laws, the practice of medicine legally occurs in the jurisdiction where the patient is physically located at the time of a clinical encounter or telehealth visit. Consequently, a physician evaluating a patient or trial participant via audio-video telehealth across state lines must hold an active medical license issued by the patient’s state medical board (subject to limited statutory exceptions).

Crucially, the IMLC does not issue a single national or “multistate compact license.” Instead, the Compact harmonizes primary-source credential verification across participating state medical boards:

• Each member state medical board issues its own independent, full, and unrestricted state medical license to the qualifying physician;
• The physician pays the applicable state license issuance and renewal fees directly to each selected member board; and
• The physician remains subject to the Medical Practice Act, continuing medical education (CME) rules, and disciplinary authority of every state in which they hold an IMLC-facilitated license.

How Does the Interstate Medical Licensure Compact Work?

The IMLC application workflow operates in four sequential stages coordinated between the IMLCC portal, the physician’s State of Principal License (SPL), and the target member boards:

1. Designation of a State of Principal License (SPL): The physician selects a Compact member state that is actively serving as an SPL, where the physician already holds a full, unrestricted medical license and satisfies at least one statutory nexus requirement.
2. SPL Primary-Source Verification & FBI Background Check: The physician submits an application through the IMLCC portal and completes a fingerprint-based Federal Bureau of Investigation (FBI) criminal background check reviewed by the SPL board. The SPL verifies medical education, graduate medical training, examination history, board certification, and disciplinary records against primary sources (including FSMB Physician Data Center and NPDB checks), complementing standard CAQH ProView and hospital credentialing and privileging workflows.
3. Issuance of the Letter of Qualification (LOQ): Once the SPL confirms that the applicant satisfies every statutory requirement of the Compact, it issues an official Letter of Qualification (LOQ). An LOQ remains valid for 365 days from its date of issuance.
4. State Selection & Expedited License Issuance: Using the active LOQ, the physician selects one or more participating member state medical boards and remits each state’s statutory license fee. Because the SPL has already attested to the physician’s eligibility via the LOQ, receiving member boards issue a full state medical license without repeating primary-source medical school or residency verification.

State of Principal License (SPL) Nexus Requirements

To designate a participating Compact state as their SPL, a physician must hold a full, unrestricted medical license in that state and satisfy at least one of the four statutory connection criteria below:

SPL Nexus Option	Statutory Requirement Under the Compact
1. Primary Residence	The State of Principal License is the state of the physician’s primary legal residence.
2. 25% Practice Threshold	At least 25% of the physician’s practice of medicine occurs within the State of Principal License.
3. Location of Employer	The physician’s employer (the person, organization, or healthcare facility employing the physician to practice medicine) is located in the State of Principal License.
4. Federal Tax Residence	The physician uses the State of Principal License as their state of residence for U.S. federal income tax purposes.

The Nine Statutory Physician Eligibility Criteria

Because member boards rely on the SPL’s Letter of Qualification to issue an expedited license, the IMLC statute (Section 2(k) of the Model Compact Legislation) enforces strict, non-discretionary eligibility standards. If a physician fails any single criterion below, they cannot use the Compact pathway and must instead apply directly to individual state medical boards through traditional licensure by endorsement:

1. Accredited Medical School Graduation: Graduated from a medical school accredited by the Liaison Committee on Medical Education (LCME) or the Commission on Osteopathic College Accreditation (COCA), or a medical school listed in the International Medical Education Directory (IMED) / World Directory of Medical Schools equivalent approved by the IMLCC.
2. Three-Attempt Exam Limit: Passed each component of the USMLE (United States Medical Licensing Examination) or COMLEX-USA (Comprehensive Osteopathic Medical Licensing Examination), or an accepted predecessor examination (NBME, FLEX, or LMCC), in no more than three attempts for any component.
3. Accredited Residency Completion: Successfully completed graduate medical education (GME) approved by the ACGME (Accreditation Council for Graduate Medical Education) or the AOA (American Osteopathic Association).
4. Specialty Board Certification: Holds current specialty certification or time-unlimited specialty certification recognized by the American Board of Medical Specialties (ABMS) or the American Osteopathic Association Bureau of Osteopathic Specialists (AOABOS). (Board eligibility alone does not satisfy the Compact statute.)
5. Zero Criminal Convictions or Deferred Adjudications: Has never been convicted, received adjudication, deferred adjudication, community supervision, or deferred disposition for any felony or misdemeanor offense by a court of appropriate jurisdiction.
6. Zero Medical License Disciplinary History: Has never held a license authorizing the practice of medicine subjected to disciplinary action by a licensing agency in any state, federal, or foreign jurisdiction (excluding actions related solely to the non-payment of fees).
7. Zero Controlled Substance Actions: Has never had a controlled substance license or permit (such as a DEA registration) suspended or revoked by a state or the U.S. Drug Enforcement Administration.
8. No Active Investigations: Is not currently under investigation by a licensing agency or law enforcement authority in any state, federal, or foreign jurisdiction.
9. FBI Fingerprint Background Check: Completes a fingerprint-based criminal background check through the SPL medical board.

Role in Multi-State Telemedicine and Decentralized Clinical Trials

In clinical operations and telemedicine credentialing by proxy, the IMLC solves state licensure verification while leaving facility-level privileging and DEA controlled-substance registration distinct. Principal investigators (PIs) and sub-investigators overseeing remote participants in decentralized clinical trials (DCTs) use IMLC-issued licenses to satisfy state-of-participant licensure mandates under FDA decentralized trial guidance, while coordinating separate state controlled-substance registrations where investigational protocols involve scheduled medications.

Sources

• Interstate Medical Licensure Compact Commission (IMLCC). Compact Statute, Physician Eligibility Requirements, and State of Principal License Rules. https://www.imlcc.org/
• Federation of State Medical Boards (FSMB). Interstate Medical Licensure Compact (IMLC) Policy & Regulatory Overview. https://www.fsmb.org/advocacy/interstate-medical-licensure-compact/