A dentist’s clinical decisions guide the procedures performed, but accurate documentation using the correct CDT codes is crucial for proper claim submission and reimbursement. Every procedure must be documented in both the patient’s dental record and the claim form using current CDT codes. However, unfamiliarity with CDT code categories, annual updates, and payer rules often leads to dental billing errors due to CDT codes, which can delay payments, trigger claim rejections, or even lead to potential legal issues. To stay compliant and avoid costly CDT coding mistakes, many dental practices turn to professional dental billing services that ensure precise coding and documentation.
Recognizing the most frequent CDT coding errors is the first step toward improving claim accuracy and maintaining steady revenue flow.
Struggling with claim denials?
Ensure precision and boost revenue with our dental billing services!
Five Common CDT Coding Mistakes in Dental Billing
- Using the wrong CDT code
Selecting the wrong CDT code for the service or procedure rendered is the most common mistake. This happens because of unfamiliarity with codes or confusion between similar codes.
CDT codes are categorized as follows:
- Diagnostic: D0100-D0999
- Preventive: D1000-D1999
- Restorative: D2000-D2999
- Endodontics: D3000-D3999
- Periodontics: D4000-D4999
- Prosthodontics/removable: D5000-D5899
- Maxillofacial prosthetics: D5900-D5999
- Implant services: D6000-D6199
- Prosthodontics/fixed: D6200-D6999
- Oral and maxillofacial surgery: D7000-D7999
- Orthodontics: D8000-D8999
- Adjunctive general services: D9000-D9999
Unfamiliarity with the nomenclature or descriptor of CDT codes could lead to choosing a code that doesn’t reflect the services provided.
Solution: Reviewing the clinical notes can identify the service provided and the appropriate category in the CDT coding manual to find the correct code match. Each procedure code entry includes both the CDT code and its official nomenclature. While some codes have specific and unique descriptors, others fall under categories or subcategories that share a common descriptor applicable to all codes within that group.
To ensure correct code selection, “the full CDT Code entry as published in the current CDT manual must be considered when determining which dental procedure code should be used to document services provided” (ADA).
Carefully verifying the complete code entry will provide the information needed to determine which code most accurately describes the procedure the dentist performed.
- Unbundling
This dental coding error occurs when multiple individual CDT codes are billed for services that are typically included within a single, comprehensive code. Here are three examples of unbundling:
- Billing for suture removal separately after extractions.
- Billing for pins as a separate service when they are included in a core buildup code (D2950).
- Billing for intra-operative radiographs separately during root canal therapy.
Insurance companies often have established rules about which procedures are considered bundled together. Unbundling can lead to claims being denied, downcoded (paid at a lower rate), or audits, penalties, and even legal action.
Solution: To avoid unbundling, dentists should:
- Understand the inclusive nature of certain procedures to select the most appropriate, comprehensive CDT code for services rendered.
- Refer to the ADA’s Code on Dental Procedures and Nomenclature (CDT) for accurate coding guidance.
- Be familiar with the bundling rules of the insurance plans your dental practice participates in, as these may impact code selection and reimbursement.
- Upcoding and Downcoding
Upcoding refers to using a CDT code for a more complex or expensive procedure than was actually performed. For example, instead of correctly coding for preventive services, a provider might mistakenly—or intentionally—submit a code for a more expensive restorative or periodontal procedure, leading to overpayment and potential compliance issues.. It can also result in inaccurate information in the patient’s medical record.
Examples: The procedure performed was a routine adult cleaning (D1110 – prophylaxis, adult) but the dental office billed scaling and root planing (D4341 – per quadrant).
D4341 is for therapeutic periodontal treatment, while D1110 is for routine dental cleaning for adult patients. Billing D4341 for a simple, preventive cleaning overstates the service.
D1110 vs D4910 confusion can also lead to upcoding. D1110 (Adult Prophylaxis) is a routine preventive cleanings in patients with healthy periodontium or mild gingivitis. D4910 (Periodontal Maintenance) is used after active periodontal therapy (such as scaling and root planing) and includes more intensive care to maintain gum health in patients with periodontal disease. If a patient has not had periodontal treatment or does not have a periodontal diagnosis, but the provider bills D4910 instead of D1110, this is considered upcoding.
Downcoding is the opposite of upcoding–using a less complex or expensive code than what was actually done. Assigning a lower-level CDT code than is warranted by the service performed can lead to reduced reimbursement or claim denials for the practice, and potentially higher out-of-pocket costs for the patient.
Example: Performing a comprehensive oral evaluation – new or established patient (CDT Code D0150), but billing Periodic oral evaluation – established patient (CDT Code D0120) instead.
Billing D0120 instead of D0150 underrepresents the complexity of the service and results in lower reimbursement.
Solution
- Use the correct CDT code definitions. Always refer to the latest ADA CDT coding manual to understand what each code represents, including its nomenclature and any applicable descriptors.
- Avoid choosing codes based on reimbursement assumptions. Do not choose a code simply because it pays more (upcoding) or is more likely to be approved (downcoding). Code strictly based on what was clinically performed.
- Regularly train billing and clinical staff to help ensure everyone involved understands proper code selection and the risks of incorrect billing.
- Medical Necessity Errors
Medical necessity refers to services or procedures that are justified as reasonable, necessary, and appropriate based on clinical standards. Dentists must clearly document the medical necessity of the procedures performed. Billing errors related to medical necessity can result in dental claim rejections or reduced reimbursements if the insurance company determines that a procedure was not essential for the patient’s oral health
Solution: When reporting CDT codes for any procedure, provide evidence to support its medical necessity. This includes patient history, clinical findings such as examination results and diagnostic tests (like X-rays or sleep studies), treatment plan and rationale, and supporting documents.
Properly documenting medical necessity helps prevent claim denials, ensures that patients receive the necessary treatment for their health conditions, and promotes appropriate reimbursement.
- Using Outdated or Deleted Codes
Each year The ADA updates CDT codes to accommodate new changes to dental procedures. If practices do not keep pace with key code changes, it can lead to using outdated or deleted codes and result in denied claims. Though the CDT Manual provides complete nomenclatures and descriptors for each CDT code, these details are often missing from software updates. Many practice management systems tend to truncate this information, making it more challenging for dental teams to select the correct code with confidence. Correcting and resubmitting claims is a costly process.
Solution: Ensure that claims are submitted using the most current CDT codes recognized by insurance payers by updating your coding references annually. Provide training for your team each year on newly added, revised, and deleted CDT codes to maintain compliance and accuracy.
Outsourcing: A Reliable Strategy for CDT Coding Compliance in Dental Practices
Up-to-date knowledge, accurate documentation, and a deep understanding of payer-specific rules are essential for navigating the challenges of CDT coding. Even minor CDT coding mistakes—like selecting the wrong code, misunderstanding descriptors, or failing to justify medical necessity—can result in delayed payments, claim denials, and compliance risks.
Outsourcing to a trusted dental billing company can significantly reduce the risk of coding errors. Professional teams in billing companies stay current with annual CDT updates, understand payer policies, and can ensure claims are submitted accurately and compliantly. By investing in specialized support, dental practices can improve claim acceptance rates and maintain a healthy revenue cycle while focusing on delivering quality care.
Partner with us to eliminate coding errors and maximize your reimbursement.
More from This Author
