Frequent General Questions Regarding Dental Procedure Codes

When it comes to the Code on Dental Procedures and Nomenclature, better known as the CDT Code, most dentists have similar questions about this ADA intellectual property. The questions (and answers) below, compiled by the ADA Practice Institute, are often asked by ADA members who seek a general understanding of the CDT Code, and who are interested in how their own unique questions can be addressed.

ADA has also developed a comprehensive reference library with coding educational material for dentists. Here you will find videos, webinars and PDF guides that provide an in-depth look, as well as focused questions and answers, on specific services that are documented and reported with their own unique CDT Codes. These items are found on the ADA’s Coding Education web pages and available for purchase through the ADA Store.

The CDT 2023 and Coding Companion Kit with App includes:

1. Why is the CDT Code updated annually?

Dental procedures continually evolve and the CDT Code provides a means to document services that dentists are delivering.  Annual updates enable the CDT Code to effectively accommodate that evolution.  As a named HIPAA national standard for electronic claims transactions, the ADA is obligated to review the CDT Code annually.

2. Who requests CDT Code additions, revisions or other changes?

You do – Dentists, as primary providers of dental care, are an important source of requests for additions and revisions. Requests also come from the ADA’s Council on Dental Benefit Programs, dental specialty organizations, third-party payers, and others in the dental community. The maintenance process is open to anyone who is interested, which is why “how-to” and “when” information is posted online at the CDT Code page.


3. How do I know which CDT Code is appropriate to document the service I delivered?

A dentist’s clinical decisions determine what services (procedures) are delivered to a patient. The full CDT Code entry, as published in the CDT manual, must be considered when determining which dental procedure code should be used to document services provided. A procedure code entry consists of the code with its nomenclature, which are printed in boldface type. Some procedure code entries also have descriptors printed in regular typeface. A careful reading of the code entry should provide the information needed for a dentist to decide which code most accurately describes the procedure that was performed. Codes should not be chosen based on what will gain the most reimbursement.

4. Why is there no CDT Code for the procedure I am providing today?

There are times when delivery of new or modified dental procedures and the CDT Code maintenance process are not synchronized. The change to annual CDT Code update helps keep procedures and documentation in step. Yet, there will be situations where, in the opinion of the dentist, no CDT Code entry accurately describes the service provided. This is when an "unspecified …procedure by report" CDT Code may be considered (e.g., D2999 unspecified restorative procedure, by report). All "by report" procedure codes must include documentation that explains the service provided. In addition, this is an opportunity for you to submit a CDT Code action request to fill the gap.

5. Who do I call for more information about the CDT Code or claim submission?

CDT Coding assistance is available to all ADA members, plus any non-member who has purchased the current manual. Coding matters are forwarded to the Center for Dental Benefits, Coding and Quality staff, who are within the Practice Institute. Contact the ADA Member Service Center (MSC) at 800.621.8099 or via e-mail at

6. What other CDT Code information is online?

There are webinar recordings and guides to specific procedures and their CDT codes that may be viewed online or downloaded at no cost from the Coding Education web pages. Topics and codes covered include case management services, scaling in the presence of gingival inflammation, teledentistry events, and more.

7. Why don't third-party payers cover all CDT Code procedures?

The CDT Code is a taxonomy that enables codified documentation of services provided. A dental benefit plan reflects the purchaser’s decision on what services will be covered for plan’s cost. This is why dental benefit plan documents contain coverage limitations and exclusions provisions.

8. Doesn't HIPAA require a third-party payer to cover every procedure code listed on a claim submission?

No, HIPAA's administrative simplification provisions are limited to standards for information exchange between the sender (e.g., a dentist/practitioner; provider) and the recipient (e.g., dental benefit plan / aka third-party payer). HIPAA says that information must be exchanged in a standard format and use specific code taxonomies, which includes the CDT Code. HIPAA's administrative simplification provisions do not determine what you do within your practice, or what a payer does in its individual claim adjudication policies.

9. Why isn't the CDT Code available at no cost to members?

The Code on Dental Procedures and Nomenclature is important and valuable ADA intellectual property, and it has significant maintenance costs. Volunteer leadership views non-dues revenue, through CDT publication sales and licensing, as a means to offset a portion of the maintenance cost.

10. Why do I need a CDT Manual when my practice management system vendor sends a procedure code update as part of my maintenance package?

The CDT Manual includes information that is often omitted in software updates – a detailed listing of procedure code nomenclature and descriptor changes and complete nomenclatures and descriptors applicable to every CDT Code entry. Practice management systems routinely truncate this information which makes choosing the correct code more difficult.

11. What is the relationship between the CDT Code and SNODENT?

These code sets each have a different purpose, but with one area overlap. The CDT Code enables codified documentation and reporting of dental procedures. It is a HIPAA standard applicable to electronic dental claims. On the other hand, SNODENT (Systemized Nomenclature for Dentistry) supports codified description of the patient's condition (e.g., diagnosis and findings) and other factors that may affect treatment. It is not a HIPAA standard and may not be reported on a dental claim. Use of the CDT Code and SNODENT does overlap in one area – both are recognized by federal agencies as code taxonomies to be used on Electronic Health Records of dental patients.

12. What is the relationship between the CDT Code and ICD Codes?

Both the CDT Code and ICD Codes are HIPAA standards applicable to electronic dental claims. ICD (International Classification of Diseases – 10th Edition – Clinical Modification) is the only diagnosis code set that may be used on claims submitted to dental benefit plans when needed, as well as on claims for dental services submitted to medical benefit plans where diagnosis codes are always required. Take a look at examples of frequently reported CDT Codes with one or more possible ICD-10-CM diagnostic codes. The CDT Code is maintained by the ADA Council on Dental Benefit Programs’ Code Maintenance Committee. ICD is maintained by agencies of the federal government.

13. I've received an Explanation of Benefits that shows reimbursement either for fewer services, or for different procedure codes, than those reported on the claim. How can this happen? Isn't the third-party payer doing something wrong or illegal? It looks like the CDT Code is being misused.

An explanation of benefits that shows reimbursement for fewer services or for different procedure codes than reported on the claim raises eyebrows and prompts dentists to call the ADA and ask, "How can this happen? Isn' the third-party payer doing something wrong or illegal? It looks like the CDT Code is being misused." The first step in answering these questions and concerns is to look at what guidance is in place concerning CDT Code use.

  • A third-party payer is supposed to use the code number (e.g., Dxxxx), its nomenclature and its descriptor as written. The ADA is interested in hearing about instances where the payer has changed any of them.
  • The ADA defines procedure code bundling as “the systematic combining of distinct dental procedures by third-party payers that results in a reduced benefit for the patient/beneficiary.” Procedure code bundling is frowned upon by the ADA. However, dentists who have signed participating provider agreements with third-party payers may be bound to plan provisions that limit or exclude coverage for concurrent procedures. 
  • The Health Insurance Portability and Accountability Act (HIPAA) requires the procedure code reported on a claim be from the CDT Code version that is effective on the date of service. Yet neither HIPAA, ADA policy nor the CDT Code itself require that a third-party payer cover every listed dental procedure. Covered dental procedures are identified in the contract between the plan purchaser and the third-party payer.

Many patients do not understand how dental benefit programs work and that coverage limitations and exclusions may limit reimbursement for necessary care. Such a misunderstanding is compounded when EOB language suggests that the dentist is at fault. Ensuring patients understand the limitations of their dental plan prior to treatment may help avoid problems and maintain a strong dentist-patient relationship.

Some dental claim adjudication practices are appropriate when based on plan design and should be clearly explained on the EOB to prevent misunderstandings. Other situations, where the EOB message suggests the dentist is in error, may pose problems. Each of these conditions is illustrated in the following examples:

Acceptable EOB explanation: A claim for a “D4355 full mouth debridement…” and a two-surface restoration is adjudicated and only the D4355 is reimbursed. The EOB message states that the benefit plan has limitations and exclusions, one of which is that the plan does not cover any restorative procedure delivered on the same day as a D4355. In this example the payer has not paid for the procedure due to benefit plan design limitations – there is no suggestion that the dentist has done anything improper.

Unacceptable EOB explanation: The dentist reports a D1110 on the claim because the patient is 13 years old with predominantly adult dentition, but the EOB lists D1120 with a message that this is the correct code for a patient under the age of 15. In this example the payer is wrong, as the message implies that the dentist reported the incorrect prophylaxis procedure code. Here the payer ignored the CDT Code’s descriptor where dentition, not age, is the criterion for reporting an adult versus child prophylaxis. What the payer should do when the benefit plan specifies an age-based benefit limitation, is accept the claim as submitted and note on the EOB that the claim has been adjudicated based on benefit plan design.

The last example illustrates why it is important that the dental office help the patient understand the clinical basis for treatment. In this case the type of prophylaxis is determined by the state of the patient’s dentition, not age, even though the patient’s benefit may be determined by age.

14. The insurance company has denied a claim for procedure code D4212 (gingivectomy or gingivoplasty, to allow access for restorative procedure, per tooth), saying that it is always an integral part of the restorative procedure submitted on the claim. Doesn't this look like the company is violating its CDT license by redefining the codes?

A D4212 and a restorative procedure are separate and distinct clinical services. The insurance company may not redefine either one or both. If however, the dental benefit plan does not provide a benefit for D4212, the denial must state that there is no reimbursement due to benefit plan limitations and exclusions. The payer should not disallow this procedure based on bundling.

Accurate patient record-keeping requires that all services delivered to a patient be fully documented. An insurance company's adjudication policies are completely separate matters. If you experience this type of situation, please contact ADA.