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Current procedural terminology; a primer
  1. Joshua A Hirsch1,
  2. Thabele M Leslie-Mazwi2,
  3. Gregory N Nicola3,
  4. Robert M Barr4,
  5. Jacqueline A Bello5,
  6. William D Donovan6,
  7. Raymond Tu7,
  8. Mark D Alson8,
  9. Laxmaiah Manchikanti9,10
  1. 1Neuroendovascular Program, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
  2. 2Neuroendovascular Program, Massachusetts General Hospital, Boston, Massachusetts USA
  3. 3Hackensack University Medical Center, Hackensack, New Jersey, USA
  4. 4Mecklenburg Radiology Associates P.A., Charlotte, North Carolina USA
  5. 5Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York, USA
  6. 6Norwich Diagnostic Imaging Associates, Norwich, Connecticut, USA
  7. 7Department of Progressive Radiology, The George Washington University, Falls Church, Virginia, USA
  8. 8Sierra Imaging Associates, Clovis, California, USA
  9. 9Pain Management Center of Paducah, Paducah, Kentucky, USA
  10. 10Anesthesiology and Perioperative Medicine, University of Louisville, Louisville, Kentucky, USA
  1. Correspondence to Dr Joshua A Hirsch, Neuroendovascular Program, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Hirsch{at}


In 1966, The American Medical Association (AMA) working with multiple major medical specialty societies developed an iterative coding system for describing medical procedures and services using uniform language, the Current Procedural Terminology (CPT) system. The current code set, CPT IV, forms the basis of reporting most of the services performed by healthcare providers, physicians and non-physicians as well as facilities allowing effective, reliable communication among physician and other providers, third parties and patients. This coding system and its maintenance has evolved significantly since its inception, and now goes well beyond its readily perceived role in reimbursement. Additional roles include administrative management, tracking new and investigational procedures, and evolving aspects of ‘pay for performance’. The system also allows for local, regional and national utilization comparisons for medical education and research. Neurointerventional specialists use CPT category I codes regularly—for example, 36 215 for first-order cerebrovascular angiography, 36 216 for second-order vessels, and 37 184 for acute stroke treatment by mechanical means. Additionally, physicians add relevant modifiers to the CPT codes, such as ‘−26’ to indicate ‘professional charge only,’ or ‘−59’ to indicate a distinct procedural service performed on the same day.

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Neurointerventional (NI) specialists benefit from understanding the Current Procedural Terminology (CPT) system and its associated process, its historical development and evolution, and its present day function. We present this information in the context of our prior manuscripts, which discussed present day challenges affecting component coding, and the Relative Value Scale Update Committee (RUC)—the American Medical Association (AMA)/specialty society RUC.1 ,2

In addition, we relied on two excellent reference articles published by Dr Thorwarth in JACR.3 ,4 Finally, the AMA provides substantial information on CPT on its own publicly available website.5

The great society of Lyndon Johnson was in full throttle and in 1965, Congress created Medicare under Title XVIII of the Social Security Act with the stated purpose of providing health insurance to Medicare beneficiaries aged ≥65, regardless of income or medical history. At this time of innovation, medical care was becoming increasingly complicated. It was believed that developing a coding system to describe medical procedures would be beneficial. Therefore, the AMA developed the first version of the CPT system, with input from a number of major medical specialty societies. Medicine has progressed substantially in this past half century—as shown by the development of the NI field, among others—requiring regular modification and updating of the CPT system. Terminology and coding developed in 1966 would have little applicability to current practice.

The Health Insurance Portability and Accountability Act (HIPAA) of 1996 (the Kennedy–Kassebaum Act) included a requirement that the Department of Health and Human Services (HHS) name national standards, including specifying code sets, for electronic transactions of healthcare information.5

This prompted the AMA to perform an extensive analysis of the strengths and weaknesses of the CPT system and implement change. This review resulted in an expansion of CPT beyond procedure and service reporting into the tracking of new services and procedures, as well as facilitating the reporting of measures useful for pay for performance. The revised CPT codes are accepted by Medicare for use in claims processing, and have been incorporated wholesale into Medicare's own coding system, designated the Healthcare Common Procedure Coding System (HCPCS).

Legal language is typically found with regard to CPT materials. We mention this language in this manuscript. It indicates that CPT is copyright protected by the AMA and that all rights are reserved. Additionally, it is asserted that CPT is a registered trademark of the AMA.


The first edition of CPT (1966) primarily described surgical procedures, with only small sections allotted to medicine and radiology. CPT when first established had no relationship with reimbursement. Given the germinal state of NI surgery, readers should not be surprised that there was little coding nomenclature for NI. Readers might not realize that the initial system was a four-digit coding system established with the goal of developing a set of ‘standard terms and descriptors to document procedures in the medical record’. In 1970, the second edition (CPT II) was published, expanding the individual codes to the current five digits; the 10 000–19 999 series described anesthesia procedures; 20 000–69 999 surgery; 70 000–79 999 radiology; 80 000–89 999 pathology; and 90 000–99 999 described medicine services—thus substantially expanding the listing of non-surgical procedures.5

By 1977, the AMA had released CPT III and CPT IV. By design, the nomenclature was becoming increasingly granular with each successive version. This decade of updates had taken the system to a certain point of granularity and usability but there was consensus that CPT required a more sophisticated update and review, with increased input from specialty societies and major stakeholders. In 1980 the AMA House of Delegates (HOD) developed a resolution on point, and reaffirmed it in 1990 and 2000, in house resolution H-70.998 (‘On the revision of CPT’). This resolution affirmed support, including face-to-face meetings and direct involvement of knowledgeable physicians from relevant specialties, to review all future changes for CPT.

Throughout the 1980s the CPT system became more embedded in the entire US healthcare system, leading to it becoming the de facto coding system we know today, a comprehensive coding system with annual updates. In 1983, the Health Claim Care Financial Administration (now the Centers for Medicare and Medicaid Services, or CMS) merged CPT with its own HCPCS. The Final Rule published that year by HHS selected the CPT system for reporting physician services (and other ancillary medical services). In 2000, CPT was designated as the national coding standard for reporting physician and other healthcare professional services and procedures.5

The CPT Editorial Panel

When it was recognized that there was a need for systematic CPT review with physician input, the CPT Editorial Panel was organized. The editorial panel is the forum for dealing with problems related to code set maintenance and for the development of new and revised CPT codes. It includes representation from physicians, non-physician healthcare providers, payers, and the American Hospital Association. It also includes representation from CMS and some of the major insurance companies. The Panel meets three times a year to evaluate all ‘code change proposals’ that are brought before CPT.5

The CPT Advisory Committee

The CPT Advisory Committee is the group that allows medical societies to provide input into the CPT editorial process. This large committee comprises representatives of all national medical specialty societies that have seats in the AMA HOD, as well as “organizations representing limited-license practitioners and other allied health professionals” (the Healthcare Provider Professional Advisory Committee (HCPAC).

The responsibilities of CPT advisors are multiple. They include serving as a resource to the CPT Editorial Panel; submitting code change proposals; and commenting on proposals sent by other groups (proposals can also be submitted by individuals, vendors, payers and others) that relate to their specialty's scope of practice. The CPT advisors also provide supporting clinical documentation for new procedures/services under consideration for new codes. Finally, the advisors are thought of as ambassadors, promoting and educating their societal members on the purposeful use and benefits of CPT.5 There are strict rules about disclosure and conflict of interest standards, mandated and upheld by the AMA.6

As with the RUC, these specialty society advisors work with an army of professional staff supplied by their respective organizations.1

More recent developments

The CPT process is often thought of in concert with its sister committee, the AMA Specialty Society RUC. While both have positions in the coding and payment food chain, they function in different ways by design. For example, the CPT process is designed to be more open than the RUC process—though in their current forms, both are certainly more transparent than previously. In the earlier forms, any code change requests were submitted with supporting documentation, and the CPT panel would decide whether a code change was required. Beginning in the late 1980s, the individuals/groups responsible for code change requests were allowed to present their case, though they were excused before any Panel deliberations, and were informed of the results of the CPT discourse several weeks later.3

The 1992 AMA HOD resolution H-70.973 dealt with the need to broaden participation in CPT. While much of the resolution dealt with education and encouragement, equally important was a point to enhance communications with the specialty societies about the CPT process and subsequent appeals.

In response, the CPT Editorial Panel became far more transparent, more closely resembling the body that we recognize today. Advisors and their specialty staff members are permitted to attend the full CPT meeting, including deliberations on code change proposals. Requestors are given seats at the Panel table during discussion of their proposals, and can respond directly to questions from Panel members. In addition, members of the Advisory Committee or their staff members with interest in the proposals can make comments or pose questions.

Additional steps in opening up the process were taken in recent years with the development of the AMA's CPT website, and allowing admission of anyone interested in attending a Panel meeting. This does permit press representatives to attend, but all attendees are required to sign confidentiality agreements. Votes are tabulated electronically and remain confidential, revealed only to Panel members during executive sessions. Votes are considered final when the minutes have been approved by the full Panel. An appeals process exists for those requesting reconsideration of a Panel decision (obviously most common when a proposal is rejected); therefore, Panel actions are not considered final until published in the CPT book of that cycle.3

CPT meetings are held three times a year, usually in April/May, September/October, and January/February. The January/February meeting is the last meeting to present codes for consideration in the subsequent year CPT book. For example, the last opportunity to present a code for consideration in the 2015 CPT book is the February 2014 CPT meeting.

Confidentiality, disclosure, and ethics

As with the RUC, confidentiality is taken seriously by the CPT Editorial Panel and the AMA. All those attending Panel meetings are routinely instructed not to disclose any perceived ‘results’ of the meeting to anyone beyond those in their specialty organizations who need to know—for example, for subsequent RUC valuation planning. The code change proposal form has specific questions that must be answered by requestors about any financial conflicts of interest, and presenters are specifically required during meetings to disclose any potential conflicts at the time of presentation of their proposals. As one would expect, all Panel members are required to provide signed disclosure agreements at each meeting about any potentially significant financial relationships, and to disclose any such relationships before discussion of specific proposals.

Anyone may ask for a code proposal to be submitted to CPT. Maintenance of the integrity of the CPT process is held at the highest standards; lobbying or marketing code submissions or changes is prohibited. “‘Lobbying’ means unsolicited communications of any kind made at any time (including during Editorial Panel meetings) for the purpose of attempting to improperly influence either (1) CPT/HCPAC Advisors’ or their societies’ evaluation of, or comments on, a code change request or (2) voting by members of the Editorial Panel on a code change request”.7


President Bill Clinton signed the HIPAA into law in 1996. Title I of HIPAA protects health insurance coverage when people change or lose their jobs. Title II of HIPAA is known as the administrative simplification section. Title II required the establishment of national standards for electronic healthcare transactions and national identifiers for providers, health insurance plans, and employers. During the process of selecting those standards, a set of ‘principles’ were developed against which any standard would be judged. It is contained within Title 42 of the United State Code.

With the then newly minted HIPAA Law in place, the AMA Board of Trustees established the CPT-5 project. The intention of CPT-5 was a comprehensive evaluation of CPT and the implementation of any necessary revisions to make it comply with all the ‘principles’ necessary to be considered as a national standard code set by the Department of HHS.

Overseen by the Project Advisory Group, six workgroups were established, each of which made recommendations which they reported back to the Project Advisory Group. Numerous recommendations were made, well beyond the scope of this manuscript. The priority of the CPT-5 project was to eliminate ambiguity and to have the ability to adapt to changes in technology, including the healthcare infrastructure which governs providers today. These CPT-5 actions have not had a direct effect to date on the coding activities of the typical US physician.5 ,8

Categories of CPT codes

The CPT codes we traditionally think of when working in clinical practice are termed ‘category I codes’. These have met rigorous criteria for approval. These criteria include Food and Drug Administration (FDA) clearance or approval for all necessary drugs and devices, documented clinical efficacy with a substantial body of supporting peer-reviewed literature, and common practice by many physicians across the USA. Increasingly, neurointerventionalists are hearing more about other types of CPT codes. We will review category III and category II codes next.

What are category III CPT codes?

Originally, CPT had no mechanism for tracking new procedures and technologies that did not qualify for a category I code, so category III codes were developed in 2001. They represent a set of temporary tracking codes intended to facilitate data collection that might be useful in the FDA approval process or to substantiate widespread use. Thus, the category III code proposals do not have to meet the stringent criteria associated with category I. The category III criteria include:

  • a protocol for a study of procedures being performed;

  • support from the specialties who would use the procedure;

  • availability of US peer-reviewed literature;

  • descriptions of current USA trials outlining the efficacy of the procedure.

Category III codes are assigned a numeric-α identifier (eg, 1234 T). Since category III CPT codes are intended to be used for data collection in investigational protocols and to substantiate widespread usage or in the FDA approval process, they are not intended for services/procedures that are not accepted by the CPT Editorial Panel because the proposal was incomplete, more information was needed, or the Advisory Committee did not support the proposal.5

Category III CPT codes are not referred to the RUC for valuation recommendations (remember that the RUC only recommends values to CMS) because no relative value units are assigned to these services in the CMS Medicare physician fee schedule. Payment for category III services/procedures is based on the policies of payers and local Medicare area contractors. We note parenthetically that local payment determination is conceptually a reasonable approach for category III CPT codes. It is not reasonable to categorically deny payment for CPT category III codes since they are effectively more functional versions of unlisted codes that many payers cover. Once payment policies are established for a category III code, the need for supplementary documentation is minimized since category III codes are associated with unique and specific descriptions of the service or procedure. Since category III codes are part of the CPT code set, all healthcare payers must be able to accept category III codes into their systems to comply with the standards for transactions and code sets under HIPAA. Note that the category III code set is updated twice a year to include new codes and code edits.

Category III codes are approved for a 5-year period. The theory is that by that time, the investigational protocols would have either produced sufficient data for conversion to a category I code or else would have failed to demonstrate utility, leading to ‘sunset’ of that code. It is possible to extend a category III CPT code for an additional 5 years if supported by the relevant specialty societies and approved by the Panel. Once used, category III codes cannot be reused or resurrected.5 ,9

What are category II CPT codes?

Category II codes are designated for reporting quality performance measures. For CPT to serve effectively as a national standard code set, the Editorial Panel and staff thought it imperative that a code category be developed to assist in the reporting of quality measures. The result is the recently implemented category II CPT codes. The goal is that use of the tracking codes for performance measurement will decrease the need for record abstraction and chart review, thereby minimizing the administrative burden. These codes are intended to facilitate data collection pertaining to quality of care by coding certain services and/or test results that support performance measures that have been agreed upon as contributing to good patient care. Some codes in this category may relate to compliance by the healthcare professional with state or federal law. The codes are not required for correct procedural coding and may not be used as a substitute for category I codes.

The number of category II codes is growing rapidly, and their implementation continues to increase. They are listed in a separate section of the CPT book, and can be found on the AMA's CPT website.5 Each specialty and subspecialty is encouraged to participate in the development of the performance measures and to monitor category II codes that apply to them. An example of a Category II code that neurointerventionalists might use comes from Physician Quality Reporting System (PQRS) Measure 145: Exposure Time Reported for Procedures Using Fluoroscopy. Physicians participating in a PQRS program should report Category II code 6045F when fluoroscopy is utilized.

CPT is the common language for medical procedures in all medical and surgical specialties, including radiology. Its integrity and accuracy is essential for payment and valuation purposes and also for data collection in academic and tracking studies, as well as clinical decision support research, comparative effectiveness, and imaging utilization research.10 ,11


For nearly half a century, the CPT system has been used to uniformly and accurately report and record the delivery of medical procedures and services. It is used by many US healthcare providers. With the evolving healthcare industry, the scope of the CPT code set has expanded dramatically.

We have reviewed the historical development of CPT and how the process has grown from an insular exercise to a relatively transparent, more inclusive one. We have in limited ways contrasted the CPT editorial process to the work of the ‘sister’ RUC committee.

While most readers are familiar with the category I CPT codes, with increasing frequency neurointerventionalists are dealing with category III tracking codes. Finally, as we participate with greater frequency in pay for performance and other quality and value-based initiatives, category II CPT codes may assume greater importance.


The authors would like to thank Dr William Thorwarth for reviewing the paper and sharing his expertise.



  • Contributors JAH drafted the initial manuscript. All authors reviewed that draft and provided meaningful editorial suggestions many of which were incorporated into the final version.

  • Competing interests None.

  • Provenance and peer review Not commissioned; internally peer reviewed.