CPT and CDT Codes Explained: A Guide for Dental Practices

Last updated August 5, 2026

As dental and medical care become increasingly intertwined, dental practices are encountering CPT codes more often than ever. Understanding how CPT and CDT codes differ — and when each applies — is becoming an essential part of running a well-billed dental practice.

On the surface, CPT and CDT codes appear to be the same, but the reality is that they are two very different coding systems used in the healthcare industry. The argument can be made that they are related to each other, but they’re certainly not interchangeable. That being said, as dental care and medical care become more symbiotic, chances are you will find yourself growing familiar with both. 

What Is a CPT Code?

Current Procedural Terminology, or CPT, was developed by the American Medical Association in 1966. According to the AMA, CPT codes provide “a uniform process for coding medical services that streamlines reporting and increases accuracy and efficiency. In other words, every medical procedure has a specific code that allows uniform billing across all healthcare providers, including hospitals, medical/dental offices, and insurance companies. 

What is a CDT Code? 

Current Dental Terminology, or CDT, is the set of dental procedure codes developed by the American Dental Association in 1969. According to the ADA, “supports multiple needs: e.g., documentation; billing and reimbursement; revenue; data analytics.” Just as every medical procedure has a specific code, the same applies to every dental procedure, allowing uniform billing across dental practices and insurance companies. 

CPT vs CDT: Key Differences at a Glance

What Do CPT and CDT Codes Look Like?

Both CPT and CDT codes contain five digits, but that’s where their similarity ends. CPT codes either consist of both numbers and letters or numbers alone, while CDT codes always begin with the letter D followed by 4 numbers. For example, a CPT code for a periodic oral evaluation would be 99212, while the CDT code would be D0120.

Are CPT and CDT Codes Interchangeable?

CPT codes are not allowed to be reported on the 2024 ADA Dental Claim Form. However, many medical payors will allow CDT codes to be reported on the CMS-1500 (02-12) Medical Claim Form. Most medical payors who accept CDT codes require that only one type of procedure code be reported on the claim form (i.e., per claim form, report only dental codes or only medical codes).

Do CPT Codes Apply to Dentistry?

CPT codes do apply to dentistry in certain instances — particularly when a dental procedure is medically necessary and may be covered by a patient’s medical insurance. For a full list of dental procedures commonly covered by medical insurance and how cross-coding works, see our guide: Medical-Dental Cross-Coding: Understanding CDT, CPT, and ICD Codes.

Can Dentists Bill CPT Codes?

Yes, a dentist can bill CPT codes. As medical and dental care continue to intertwine, CPT codes are becoming more common in dental offices. That’s why it’s best to verify the patient’s medical and dental insurance coverage ahead of time. Consider outsourcing this task to a knowledgeable, remote team to ease the burden of this added workload. 

What Are ICD-10 Codes?

Developed by the World Health Organization (WHO) and maintained by the CDC’s National Center for Health Statistics, International Classification of Diseases (ICD) codes are medical diagnostic codes used to code disease and medical conditions data. CPT codes apply to the treatment performed, whereas ICD codes apply to the diagnostics behind that treatment. Dental offices should use the ICD-10-CM code set to document diagnoses. NCHS provides a user-friendly, no-cost Browser Tool for the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM). 

Note: While the WHO has created a newer version (ICD-11-CM), it hasn’t been implemented in the United States as of the date of this publication.

Does Medical Coding Require Certification?

While certification for medical coding isn’t required in the United States, it can offer an advantage to those seeking employment where it applies. Medical coding does require a knowledge base of not only the codes themselves, but also the diagnostics and procedures they apply to, as well as the CMS-1500 form used to submit medical claims to insurance carriers. 

Need More Dental Billing Resources?

As dental care and medical care continue to join forces, it’s increasingly important to be aware of the differences between CDT and CPT codes, as well as the role that both CPT and ICD-10-CM codes play in a dental office. At eAssist, our dental billing professionals have experience with both medical and dental plans and can assist your office in obtaining revenue from both. To learn more, schedule a consultation today.