Mid-level practitioners, also called assistant practice clinicians and non-physician practitioner, are trained health care providers who have a defined scope of practice. This means that they are trained and legally permitted to provide healthcare in fewer situations than physicians and some other health professionals, but in more than other health professionals. For example, a mid-level provider may be trained for and legally permitted to perform some surgical procedures, but not others. They may have extensive education and a formal certificate and accreditation through the licensing bodies in their jurisdictions.
Because of their diverse histories, mid-level providers' training, functions, scope of practice, regulation, and integration into the formal health system vary from country to country. Mid-level practitioners have many different titles, e.g. physician assistant, clinical officer, or nurse practitioner.
- trained and legally authorized to provide healthcare,
- having at least two years training at university or other institution of higher education, and
- able to diagnose and treat medical conditions, within the scope of their training and licensure, by prescribing medication and/or performing surgery.
US professional organizations for nurse practitioners, nurse anesthetists, physician assistants, clinical nurse specialists, and Certified Nurse-Midwives prefer the term Advanced Practice Provider (APP). They are concerned that "mid-level" will be misunderstood as indicating that they provide only a medium quality of care to patients, or that it does not adequately convey the extent of their education, which in the US often includes a master's degree or other advanced degree in a healthcare field.
Other providers prefer their specific professional title (such as "nurse practitioner") to any category.
MLPs by country
Mid-level practitioners in the UK are known as Advanced Clinical Practitioners (ACP) and is an evolution of many differing professions which use various titles such as ‘Extended Scope Practitioner’ or ‘Advanced Practitioner’. Historically there has been debate over the consistency of quality in these senior clinicians and therefore it became necessary to generate a distinguished definition of the ACP role. The ACP:
- Is a registered healthcare practitioner with a minimum of 5 years clinical experience (2 years in a senior clinical role)
- Has acquired expert knowledge and complex decision making skills which may be an extension of their traditional scope of practice
- Will undertake a two-year level 7 (Master's degree) training course in Advanced Practice
- Will maintain training and CPD requirements 
This is an emerging role and is showing a good deal of promise in meeting the demands of the UK's rapidly evolving healthcare requirements. ACPs may practice in the acute setting (ED, critical care, medical or surgical wards) or community General Practice / family medicine. The majority can independently assess, investigate (through blood science / imaging / labs etc.), diagnose and formulate a treatment including prescribing medications or referring to specialist care.
The deployment of ACPs is considered to be part of a Value Based Recruitment framework driven by Health Education England (HEE). This seeks to appoint clinicians based upon their competencies, values and behaviours in support of collaborative working and delivering excellent patient care.
In the United States, mid-level practitioners are health care workers with training less than that of a physician but greater than that of more ordinary nurses and other medical assistants. In recent years some organizations and specialties have proposed the discontinuance of the term mid level in reference to professional practitioners who are not physicians. This shift follows a change in paradigm toward a collaborative team based care model. Other groups such as the American Academy of Family Physicians considers the term to be appropriate as it delineates a clear distinction between the training and expertise of physicians and non-physicians, and considers the term "providers" that encompasses both physicians and non-physicians to be derogatory.
The term mid-level practitioner or mid-level provider related to the occupational closure of healthcare. This concept centered around physicians as the ultimate professional responsible for healthcare. As healthcare demands have increased in the United States due to an aging population, a physician shortage and the implementation of the Patient Protection and Affordable Care Act of 2010 there has been a shift toward more independence in practice for professionals such as advanced practice nurses, pharmacists, dentists, podiatrists, dental therapists and physician assistants who were previously described as part of this category.
As an example of a shift away from the US Medicare system terms both advanced practice nurses and physician assistants as "non-physician practitioner" (NPP). Medicare will pay for emergency department services when these services meet the specific critical care services definition and requirements.
The American Academy of Nurse Practitioners (AANP) released a position statement in 2009, updated in 2010, 2013 and 2015 denouncing the use of several relegating terminology. Terms such as "mid-level provider," "physician extender," "limited license provider," "non-physician provider," and "allied health provider" when referring to nurse practitioners are considered derogatory by the AANP. The American Academy of Nurse Practitioners prefers that nurse practitioners are referred to as "Nurse Practitioners," "independently licensed providers," "primary-care providers," "health-care professionals," and "clinicians." in reference to the legal and professional paradigm that nursing practice is considered separate and independent of other licensed professionals. The American Association of Nurse Anesthetist (AANA) released a position statement in 2016, updated in 2018, which opposes descriptors such as “mid-level practitioner,” “non-physician,” “physician extender,” “dependent practitioner,” and “allied health practitioner” to refer to CRNAs either individually or as part of a group; instead, the AANA recognizes the terms Certified Registered Nurse Anesthetist, CRNA, and nurse anesthetist (additional descriptors include: “Advanced Practice Registered Nurse (APRN),” “Licensed Nurse Practitioner (LNP),” “Licensed Independent Practitioner (LIP)”, Advanced Practice Provider (APP),” “advanced practice professional” or “nurse anesthesiologist”).  In a fact sheet released in 2015, the National Association of Pediatric Nurse Practitioners objects to the terminology "mid-level health care professionals" as it implies that Nurse Practitioners "provide 'average' care instead of 'high level' care".  Physician professional organizations such as the American Academy of Emergency Medicine utilize the term "Advanced Practice Provider (APP)" for these clinicians. 
Drug Enforcement Administration
The term mid-level practitioner as found in the DEA classification in Section 1300.01(b28), Title 21, of the Code of Federal Regulations is used as a means of organizing drug diversion activities. The term mid-level practitioner as defined by the DEA Office of Diversion Control, "...means an individual practitioner, other than a physician, dentist, veterinarian, or podiatrist, who is licensed, registered, or otherwise permitted by the United States or the jurisdiction in which he/she practices, to dispense a controlled substance in the course of professional practice." Some health professionals considered mid-level practitioners by the United States DEA include:
- Allied health professions
- Health human resources
- Nurse Practitioner
- Nurse Anesthetist
- Advanced Practice Registered Nurse/Advanced Practice Nurse
- Certified Nurse‐Midwife
- Physician Assistant
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