In the United States, Physician Assistants (PAs) are non-physician clinicians licensed to practice medicine with a physician's supervision. This supervision, in most cases, need not be direct or on site and many PAs practice in remote or underserved areas in satellite clinics. PAs can treat patients and, in most states, prescribe medicine, and in some states in the US they carry a DEA number that gives them authority to prescribe controlled medications like narcotics. PAs in surgical practices also serve as first assists in surgery. PAs provide medical services that are reimbursed under Medicare and third party insurances.

Physician Assistants held about 65,000 jobs in 2005. The number of jobs is greater than the number of practicing PAs because some hold two or more jobs. For example, some PAs work with a supervising physician, but also work in another practice, clinic, or hospital. According to the American Academy of Physician Assistants, there were about 58,665 certified PAs in clinical practice as of January 2006.

Just over 56 percent of PAs worked in the offices and clinics of physicians in 2005, either allopathic or osteopathic. About 36 percent were employed by hospitals. The rest were mostly in public health clinics, nursing homes, schools, prisons, home health care agencies, and the United States Department of Veterans Affairs. According to the American Academy of Physician Assistants, about 17 percent of all PAs provide health care to rural communities and those with fewer than 20,000 residents, in which physicians may be in limited supply.

In 2006, there are more than 130 accredited PA programs in existence in the United States. They are all accredited by one body -- the Accreditation Review Commission on Education for the Physician Assistant (ARC-PA). A majority of them are master's degree programs (requiring GRE for entry), but some are available as an undergraduate major. A number of these undergraduate programs are making a transition to graduate level training.

A Physician Assistant may use the post-nominal initials PA, RPA, PA-C or RPA-C, where the R indicates Registered and the C indicates "Certified." The "R" designation is unique to only a couple of states; most Physician Assistants use the PA-C. The certification is granted by one certifying body, the National Commission on Certification of Physician Assistants (NCCPA).

Physician Assistants and Nurse Practitioners both provide similar services in most states, the major distinction being that nurse practitioners are registered nurses by trade. Nurse Practitioners require more training than physicians assistants, such as a Masters Degree in nursing. Both are also known as Advanced Practice Clinicians (APCs) or mid-level practitioners (MLPs).

PAs should not be confused with Medical Assistants, who perform routine clinical and clerical tasks in a physician's office. A Medical Assistant (MA) is a multi-skilled allied healthcare practitioner who is competent in both a wide variety of clinical and laboratory procedures, as well as many administrative roles. Medical assistants have been described as healthcare's most versatile, multifaceted professionals. Medical Assisting is an allied health profession whose practitioners function as members of the health care delivery team and perform administrative and clinical procedures.

Formal education of medical assistants usually occurs in vocational or technical institutes, community colleges, proprietary schools, or junior colleges. The course length usually ranges from 1 to 2 year programs, complete with externships. The curriculum presented must always be accredited if its graduates plan to become either certified or registered. In 2002, there were 495 medical assisting programs accredited by the Commission on Accreditation of Allied Health Education Programs (CAAHEP) and about 170 accredited by the Accrediting Bureau of Health Education School (ABHES). Accreditation by either CAAHEP or ABHES usually requires that the schools curriculum provide sufficient classroom, lecture, and laboratory time (if applicable) to each of the courses below.

Administrative Courses

Computer Applications

Manual Recording of Patients? Data

Scheduling Appointments

Maintaining medical Records

Word Processing/Typewriting/Keyboarding

Coding/Insurance

Telephone Triage

Personnel Management

General Courses

Anatomy and Physiology

Behavioral Psychology

Pathophysiology

Medical Terminology

AIDS/HIV

Patient Education

Medical Law and Ethics

Clinical Courses

Phlebotomy

l Medical Asepsis/Infection Control

Pharmacology/Administration of Medications

Assisting Techniques/Physical Examination

Assisting with Minor Surgery

Basic Laboratory Procedures/Routine Blood and Urine Testing

Cardiopulmonary Resuscitation (CPR)

X-Ray Theory and Positioning

Electrocardiogram (EKG)

Certification is a voluntary process which is strongly backed by the AAMA and a number of other well respected certification bodies in the USA as a way to guarantee competency of a medical assistant at a job-entry level. However, in order to be eligible for certification one must attend a school which has been accredited by either CAAHEP or ABHES. Certification is usually achieved by taking a test issued by the National Board of Medical Examiners and AAMA, or AMT, or NHA and is offered twice yearly, simultaneously, at over 200 different test sites across the United States.

Successful completion of the rather intense exam earns the taker the proper credentials to become a Certified Medical Assistant, or CMA. National certification is legally required in order for any medical assistant to adhere to CMA status. The title CMA then follows postnominally.

Recertification must occur every 5 years in order for one to maintain their credentials. There are two ways to do this; one may either continually earn continuing education hours by attending CMA meetings, conventions and seminars, or by completely retaking the initial exam to prove they still possess a certain level of knowledge.

A medical assistant may choose another possible credential over CMA, and become a Registered Medical Assistant (RMA) instead. Again, credentialing is completely voluntary. The American Technologists (AMT) agency is responsible for certifying MAs who choose this course.

AMT first began offering this certification in 1972 on the months of June and November, through a computerized exam, much like the one offered by the AAMA. AMT therefore has its own conventions and committees, bylaws, state chapters, officers, registrations and revalidation examinations.

To become eligible to hold the title of RMA a student must be at least 18-years-old, pass a medical assisting curriculum at a school accredited by either ABHES or CAAHEP and possess a minimum of 5 years experience. The initials RMA then follow the individual's name.

RMAs have historically been very active in legislation, seeking protection for medical assistants, as well as continuously encouraging improved educational curriculums.