Medical-Dental Cross-Coding: Understanding CDT, CPT, and ICD Codes

September 26, 2017

Updated 12/2026

Dental and medical insurance often require different codes for their claims. Unlike dental insurance, which requires CDT codes for claims, medical insurance requires CPT (Current Procedural Terminology) codes for claims. International Classification of Diseases (ICD) codes for medical diagnoses and diseases establish the medical necessity behind the procedure performed (CDT/CPT). While only certain dental claims require ICD codes, all medical claims require them. Understanding these code sets and how they work together can help you maximize your patients’ dental and medical benefits.

Medical Insurance and Dental Treatment

Medical insurance may cover some dental treatments when medically necessary for patients. For medically necessary treatments, claims are typically sent to the health insurance plan first. After medical insurance reviews it, practices can then send the claim to the dental insurance plan along with a copy of the medical insurance EOB. Some health insurance payors allow CDT codes to be reported on the medical claim, while others require CPT codes.

Dental Procedures Commonly Covered by Medical Insurance

Examples of procedures that may be covered under medical insurance include (but are not limited to):

• Treatment required following an accidental injury (including dental restorations)
• Biopsies
• Cancer-related screening and treatment
• Oral appliances for the treatment of obstructive sleep apnea
• Frenectomy for newborns with feeding problems
• Treatment required to correct congenital malformations
• Evaluation and some treatment for temporomandibular joint disorders (TMD/TMJ)
• Removal of supernumerary and impacted/embedded teeth

Medical-Dental Billing and Cross-Coding

Medical–dental billing allows providers to maximize reimbursement opportunities for patients whose conditions overlap the medical and dental realms. Translating or “cross-coding” these procedures accurately ensures compliance, proper documentation, and successful claim submission. 

Why Medical-Dental Cross-Coding Is Complex

This conversion can be cumbersome because not every CDT code has a direct CPT equivalent, and interpretation often depends on clinical context and documentation. Providers must also understand related medical coding elements—such as ICD-10 diagnosis codes, modifiers, and supporting narratives—to substantiate medical necessity. For this reason, cross-coding requires both clinical knowledge and billing expertise to ensure that medically necessary dental services are reimbursed appropriately by medical insurance.

If you’re interested in learning more about how to get paid more for medically necessary dental services, download the Medical-Dental Billing Playbook today!

If you are struggling with medical dental cross-coding, consider partnering with eAssist. Our Success Consultants are familiar with cross-coding and will ensure claims are billed correctly. To learn more, schedule a consultation today.