The purpose of this article is to highlight the importance of understanding various numeric and alpha-numeric codes for accurately billing dental and medically related services to private pay or third-party insurance carriers. In the United States, common dental terminology (CDT) codes are most commonly used by dentists to submit claims, whereas current procedural terminology (CPT) and International Classification of Diseases, Ninth Revision, Clinical Modification (ICD.9.CM) codes are more commonly used by physicians to bill for their services. The CPT and ICD.9.CM coding systems complement each other in that CPT codes provide the procedure and service information and ICD.9.CM codes provide the reason or rationale for a particular procedure or service. These codes are more commonly used for “medical necessity” determinations, and general dentists and specialists who routinely perform care, including trauma-related care, biopsies, and dental treatment as a result of or in anticipation of a cancer-related treatment, are likely to use these codes. Claim submissions for care provided can be completed electronically or by means of paper forms.
Codes—what are they? And why do we use them?
International Classification of Diseases, Ninth Revision, Clinical Modification (ICD.9.CM), current procedural terminology (CPT), and common dental terminology (CDT) codes are merely a series of numbers (numeric) or letters and numbers (alpha-numeric) that are used to identify a condition, malady, disease process, etiology, procedure, or management modality. Although “one picture is worth a thousand words,” the use of one code can save the use of dozens of words. Codes are more concise than long descriptions; provide a more uniform means of communication; and bridge the gap between different languages, geographic connotations, and differences in profession, specialty, or subspecialty. They can be used to save time and space while charting or to collect demographic and frequency data for research; however, codes are a must for billing.
Billing
The advancement of medical technology throughout the twentieth century dictated a revolution of medical science. Innovation in medicine increased not only consumption of health care services but the cost of medical care, and subsequently created an increased financial responsibility for the patient, or end-consumer. This fiscal amplification produced public demand for privately held health insurance to balance and mitigate the risk for significant health care expenditure. As third-party payers began to shoulder the financial responsibility of medical care, the need was identified to interpret, classify, and establish work and reimbursement values for medical procedures submitted by myriad health care practitioners from diverse specialties, geographic areas, and training backgrounds. Standardized billing practices, in the form of uniform coding–consistent forms and documents, provide a mechanism for health care practitioners to submit succinct yet precise accounts of services rendered to third-party payers. Consistency of coding and formatting for claims permits the immediate and accurate interpretation of those services by the payer, overcoming common communication barriers. More than 500 million claims are filed to third-party health plans each month in the United States , a volume mandating the elimination of subjective, lengthy, and narrative descriptions and necessitating definitive and objective shorthand for classification of health care services.
Billing
The advancement of medical technology throughout the twentieth century dictated a revolution of medical science. Innovation in medicine increased not only consumption of health care services but the cost of medical care, and subsequently created an increased financial responsibility for the patient, or end-consumer. This fiscal amplification produced public demand for privately held health insurance to balance and mitigate the risk for significant health care expenditure. As third-party payers began to shoulder the financial responsibility of medical care, the need was identified to interpret, classify, and establish work and reimbursement values for medical procedures submitted by myriad health care practitioners from diverse specialties, geographic areas, and training backgrounds. Standardized billing practices, in the form of uniform coding–consistent forms and documents, provide a mechanism for health care practitioners to submit succinct yet precise accounts of services rendered to third-party payers. Consistency of coding and formatting for claims permits the immediate and accurate interpretation of those services by the payer, overcoming common communication barriers. More than 500 million claims are filed to third-party health plans each month in the United States , a volume mandating the elimination of subjective, lengthy, and narrative descriptions and necessitating definitive and objective shorthand for classification of health care services.
History of coding
The history of coding for medical or dental purposes can actually be traced back to London, England, in the seventeenth century . At that time, John Graunt developed a system of categorization of diseases, maladies, and conditions that attempted to identify the causes of death statistically and demographically for children younger than the age of 6 years. In 1893, based on Graunt’s work, Dr. Jacques Bertillion developed the Bertillion Classification of the Causes of Death. His system was later revised, along with a name change to the International Classification of the Causes of Death, and has historically been considered the first edition of the International Classification of Diseases (ICD). This document was refined four more times until the World Health Organization (WHO) conducted a major revision in 1948 (the sixth edition). This major revision included a section on mortality and morbidity and was renamed the Classification of Diseases, Injuries and Death. In 1958, the seventh edition was published by the WHO, and a decade later, the eighth edition was published. The ninth revision by the WHO has resulted in the ICD-9-CM. It consists of a tabular list containing a numbered roster of the disease code numbers; an alphabetic index to the disease entries; and a classification system for surgical, diagnostic, and therapeutic procedures.
The American Medical Association (AMA) developed and published Current Procedural Terminology in 1966 to define surgical procedures more clearly, with limited sections on medicine, radiology, and laboratory procedures . The second edition, which was published in 1970, included expanded terms and codes to designate diagnostic and therapeutic procedures in surgery, medicine, and the specialties. At that time, five-digit coding was introduced, replacing the former four-digit classification. In the middle to late 1970s, the third and fourth editions of the CPT code were introduced. CPT descriptive terms and identifying codes currently serve to report medical procedures and services under public and private health insurance programs and for administrative management purposes, such as claims processing and developing guidelines for medical care review. The uniform language also is applied to medical education and research to provide a useful basis for local, regional, and national use comparisons.
Before 1986, the American Dental Association (ADA) recognized the need to report dental procedures and services accurately to third-party carriers . To achieve uniformity, consistency, and specificity, the ADA developed the Code on Dental Procedures and Nomenclature ( Dental Code ). The Current Dental Terminology , first edition (CDT-1), which was released in 1991. The project to develop the CDT-1 began with a grant from the American Fund for Dental Health and took years to develop. It was a joint venture of general dentists and specialists. The CDT-2 was released in 1994 and included many revisions and additions. Initially, the dental coding system was a five-digit numeric system. The CDT-3 version was amended to an alpha-numeric system, with the first character of each code being the letter “D” to denote “dental system.” This change was initiated based on the requirements of the Health Insurance Portability and Accountability Act (HIPAA) of 1996. Developing and maintaining the CDT is the responsibility of the Council on Dental Benefit Programs. Representatives seated on the council include members from the ADA-recognized dental specialties, the Health Care Financing Administration (HCFA), and many nationally recognized payer organizations. Although the initial plan for CDT revision was to be every 5 years, more frequent revisions were found to be necessary. The most recent version, the CDT 2007 to 2008, is now available in paper and electronic formats.
Nomenclature
Numeric and alpha-numeric
Although ICD.CM and CPT coding preceded CDT coding historically, their inclusion in this article is necessary for a complete understanding of codes and their effective use. Numeric coding merely refers to the use of numbers. This is the method used by the current ICD.9.CM and CPT coding systems for medically related communications, including billing. For instance, using the ICD.9.CM coding system, dental caries would be listed as 521.0, and using the CPT system, a biopsy of the anterior two thirds of the tongue with closure would be listed as 41112. To avoid confusion with medically related codes, the CDT system used alpha-numeric, or letter and number, codes. For instance, using the CDT system, an extraction of a single tooth, including local anesthesia, suturing if needed, and routine perioperative care, would be coded as D7120. As is illustrated, the one letter and four numbers represent 16 separate words. Thus precision, conciseness, and a savings of space and time are achieved.
Descriptors
A descriptor is merely the definition or description of the code being used in the verbiage format. For the CDT code D7241, the descriptor is “removal of impacted tooth–complete bony, with unusual surgical complications.” Again, the 10 words in the descriptor are replaced by one letter and four numbers. Beyond the descriptor are further explanations of the meaning for the specific code within the code book. Again, using the example of D7241, the descriptor is followed by the following elaboration: “most or all of crown covered by bone; unusually difficult or complicated due to factors such as nerve dissection required, separate closure of maxillary sinus required or aberrant tooth position.”
Symbols
Symbols are generally used in code books to alert the reader to new or revised codes or descriptors. For instance, using the CPT coding manual, a • placed before the code number (eg, • D0170) denotes the introduction of a new procedure code in this issue of the CPT code manual. A ▴ placed before the code number (eg, ▴ D3220) identifies a revision in the nomenclature only. Finally, a ▶◀ placed before the descriptor, denotes a descriptor that has been revised since the last edition. For ICD.9.CM and CPT coding, similar symbols are used to denote new codes, changes in descriptors, and revised codes. Moreover, the ICD.9.CM and CPT coding systems use additional symbols, hollow shapes, and colored symbols to alert the user that additional information is necessary when using such codes.
Modifiers
Modifiers are not used for CDT coding; however, they are used for CPT and ICD.9.CM coding. For CPT coding, modifiers are attached to the five-number code by a hyphen to denote a comment of particular significance . In the previous illustration that denoted a tongue biopsy (41112), a -51 would be added (eg, 41112-51) for multiple biopsies. If two surgeons did the biopsy, 41112-62 would be used. There are approximately 70 CPT modifiers .
For ICD.9.CM coding, the modifiers add specificity to the diagnosis. For instance, a facial fracture is coded as 802. A closed mandible fracture is coded as 802.2, however. At the highest level of specificity, a closed fracture of the alveolus of the mandible is coded as 802.27.
Common dental terminology codes
Common dental terminology code book use
The original intent for the CDT code book was to create an educational tool for dental practitioners and their staff. Over several years, it was modified and edited, and in 1996, the Federal Government under the HIPAA designated CDT as the nationally recognized coding system for reporting dental services .
Today, CDT allows for a consistent and uniform reporting mechanism of dental services to third-party payers and imparts useful billing information for the provider. Although most third-party payers require CDT coding for claims reimbursement, it is important to remember that the existence of a CDT code does not ensure that remuneration is made. Certain codes require preauthorization or predetermination or may be specifically excluded from a dental insurance plan.
Categories of common dental terminology codes
There are currently 12 different categories of service delineated in the CDT user’s manual. For the sake of brevity, they are listed in Table 1 .
| I | Diagnostic | D0100–D0999 |
| II | Preventive | D1000–D1999 |
| III | Restorative | D2000–D2999 |
| IV | Endodontics | D3000–D3999 |
| V | Periodontics | D4000–D4999 |
| VI | Prosthodontics, removable | D5000–D5899 |
| VII | Maxillofacial prosthetics | D6200–D6900 |
| VIII | Implant services | D7000–D7999 |
| IX | Prosthodontics, fixed | D8000–D8900 |
| X | Oral surgery | D9000–D9999 |
| XI | Orthodontics | D5900–D5999 |
| XII | Adjunctive general series | D6000–D6199 |
Use of common dental terminology codes for billing
The CDT code book is the most common system of coding for dental practitioners. The code book itself is broken into eight sections :
Section 1, “Code on Dental Procedures and Nomenclature,” is divided into 12 categories of service. Each category is further divided into commonly related dental procedures. Although the category headings may denote certain specialties, it does not preclude a general dental practitioner or dental specialist from using a particular code as long as it is within the scope of the professional’s license.
The structure of the dental procedure codes includes the procedure code, the nomenclature, and the descriptor. The procedure code is a preceding five-character alpha-numeric system that begins with “D” and has a unique numeric component to distinguish each specific procedure. The nomenclature immediately follows the alpha-numeric code. This is the text naming of the procedure. The descriptor is not included for every code but can incorporate additional details or “descriptions” of the particular code. If the nomenclature indicates that the code is “by report” or “unlisted,” additional supporting documentation, such as an operative report, is required.
Section 2, “Changes to the Code,” includes additions and deletions. Any material that has been added to the code is noted in underlined blue text. Any portion that was deleted from a code is shown with a red strike-through. Any codes deleted in their entirety are also listed in this section with red strike-throughs.
Section 3, “Teeth Numbering and the Oral Cavity,” details the Universal/National System and appends the International Standards Organization System. The Universal/National System is the form used by the ADA for the dental claim form and on standard HIPAA electronic claim transactions for dental services.
Section 4, “ADA Dental Claim Form Completion Instructions,” includes instructions on how to fill out a claim form properly; use the National Provider Identifier (NPI) numbers; and relate coding for tooth numbering, tooth surface, and area of the oral cavity as used for billing purposes.
Section 5, “Questions and Answers on the Code,” is also categorized by service, just as Section 1. Each question is grouped within the category to which it relates. These questions further define the intent and use for a particular code. Additions to this section are posted on the ADA’s Web site .
Section 6, “Glossary,” defines terminology used in the nomenclature or descriptor of a code. Entries are listed in alphabetic order and are defined in simplistic nonclinical terms.
Section 7, “Numeric Index to the Code,” lists the codes by category of service in order. The page number on which the code and descriptor can be found is noted. This section also indicates any change in the code, noting whether it was an addition, deletion, or revision.
Section 8, “Alphabetic Index to the Code,” indicates or cross-references all applicable codes in alphabetic order by term and includes page number(s) on which the code and descriptor related to the term can be found.
Current procedural terminology codes
Current procedural terminology code book use
In 2000, the Department of Health and Human Services selected the CPT code book as the national coding standard for all medical professional services and procedures under the HIPAA. For all electronic medical claim submissions, CPT coding is mandated .
Categories of current procedural terminology codes
As displayed in Table 2 , there are 14 major sections of CPT codes that are based on the body system or service to be rendered . They are further divided into three major categories of code sets. Category I codes are most applicable to dentistry. The other categories of codes merely serve as an informational prospective from a dental medicine vantage point.
| Evaluation and management | 99201 |
| Anesthesiology | 00100 |
| Integumentary system | 10040 |
| Musculoskeletal system | 20000 |
| Respiratory system | 30000 |
| Cardiovascular system | 33010 |
| Digestive system | 40490 |
| Urinary system | 50010 |
| Male and female genital system | 54000 |
| Nervous system | 61000 |
| Eye and ocular adnexa | 65091 |
| Radiology | 70010 |
| Pathology and laboratory | 80048 |
| Medicine | 90281 |
Use of current procedural terminology codes for billing
The application of category I codes for billing is reviewed in the following section .
Evaluation and management services (CPT 99201–99499)
Evaluation and management (E/M) codes are divided into three broad categories: office visits, hospital visits, and consultations. There are additional subcategories. E/M services are then classified into supplementary levels as identified by particular codes. There are three basic components to consider when determining the appropriate level of service: history, examination ( Box 1 ), and medical decision making. Medical decision making is determined by three factors:
- •
The number of possible diagnoses or management options
- •
The volume and complexity of records, tests, or information considered
- •
The risk for significant complications, morbidity or mortality associated with the problem, diagnostic procedure, and management options
