Apathologists' assistant (PA or PathA) is aphysician extender whose expertise lies ingross examination ofsurgicalspecimens as well as performing hospital, medicolegal, and forensicautopsies.[1] Their education is analogous tophysician assistants, consisting of a didactic and a clinical component and concluding in amaster's degree. Certification of pathologists' assistants is through a board exam by theAmerican Society for Clinical Pathology (ASCP). In the United States, the profession is represented by theAmerican Association of Pathologists' Assistants (AAPA).
Pathologists' Assistants in theUnited States are currently only required to be licensed in three states:Nevada,West Virginia, andNew York.[2] In most other states, the scope of PAs falls underCLIAhigh complexity testing which requires an associate degree.[3]
Pathologists' assistants work under the indirect or direct supervision of a board certified anatomicalpathologist, who ultimately renders adiagnosis based on the PA's detailed gross examination and/ortissue submission for microscopic evaluation. Requirements to become a certified pathologists' assistant include graduation from aNational Accrediting Agency for Clinical Laboratory Sciences (NAACLS) accreditededucation program and successfully passing theAmerican Society for Clinical Pathology (ASCP) certificationexam, which is not legally required to perform gross examinations in most states.[2] Some states such as West Virginia, Nevada, and New York require a license for pathologists' assistants.[2] All pathologists' assistants are allied health workers who need to be CLIA 88 compliant to perform these high complexity tasks with indirect/direct supervision of a pathologist.[1] With ongoing changes inhealth care, a growing population of retiring pathologista, and a decreasing number ofpathologyresidents, well trained PAs are in high demand due to their extensive level of training and contribution to the overall efficiency of the pathology laboratory.[1]
In addition to the major responsibilities outlined above, a pathologists' assistant may also perform the following tasks (for a complete list, refer to AAPA Scope of Practice[4]):
While many PAs are employed inhospitals, they may also gain employment in private pathology laboratories/groups,medical examiner's offices,morgues,government or reference laboratories, oruniversities, and may beself-employed and providecontract work.[1]
The idea of physician extenders was conceived in 1966 by physician-educatorEugene A. Stead atDuke University, where the firstphysician assistant program was established. Three years later, also at Duke, Chairman of Pathology, Dr. Thomas Kinney established the first pathologists’ assistant program. As of June 2025, seventeen accredited programs have been established across theUnited States andCanada and six others are in various stages of accreditation.[5]
Source:[2]
While curriculum may vary somewhat from program to program, all accredited pathologists' assistants programs are two-yearmasters degrees that includedidactic andclinical training, similar to physician associate programs. The didactic year includes education in surgical and autopsy pathology, anatomy, histology, and laboratory operations. Students are then placed in a clinical setting with affiliated hospitals and/or medical examiner's offices to learn surgical and autopsy dissection.[2] Pathologists' assistant programs are accredited by NAACLS and attending an accredited program is the only route to certification by the ASCP-BOC.[6] Pathologists' assistants that have passed the ASCP certification exam use thepost-nominal letters "PA(ASCP)". PA programs collectively graduate approximately 245 students a year. As of 2024, over 3000 pathologists’ assistants have been certified.
Universities offering pathologists' assistant degrees include:
As of 6/13/2025, the programs above have the following status with the National Accrediting Agency for Clinical Laboratory Sciences:[7]
|*| Accredited
|**| Serious Applicant Status
|***| Submitted documentation to become accredited
Pathologists' assistants have been employed in pathology labs for over 40 years. Formal training programs slowly appeared (there were four nationwide in the late 1990s). NAACLS began accrediting PathA programs in the late 1990s, and then programs slowly continued their transitions from bachelor's to master's programs as their number increased. Prior to ASCP certification, which came about in 2005, the AAPA had afellowship status that program trained pathologists' assistants or on-the-job trained (OJT) pathologists' assistants (who could do specific coursework and three years of active employment) could join only based on passing a rigorous exam that parallels the current ASCPcertification exam. The OJT route was eliminated at the end of 2007. The professional association uniting PAs is theAmerican Association of Pathologists' Assistants. Part of their duties as an association is to providecontinuing medical education credits (CME) in order to keep members current on advances and procedures in the field that must be completed every three years in order to maintain ASCP certification.[5]
The 2020 novelThe Grave Below features a pathologists' assistant as a prominent character.