Your Guide to CDT Coding Mistakes and Revised CDT Codes for 2026
A recent AAPC audit of 2,600 dental claims uncovered a significant coding problem: 14% contained errors, yielding an average Current Dental Terminology (CDT) code accuracy rate of just 79%.
These inaccuracies are more than simple mistakes; they directly threaten revenue, create compliance risks, and can harm patient trust. With the revised CDT codes for 2026 on the horizon, understanding these common errors is now critical.
In this article, we will outline the most frequent CDT coding mistakes identified by the AAPC and provide the key updates you need to know for a compliant and profitable 2026.
6 Common Coding Mistakes acc to AAPC
1. 14% of errors involve over-coding of oral evaluations, screenings, and consultations.
This occurs when a dentist bills for a separate evaluation service that is already included in another procedure performed during the same visit.
- For example, using a Comprehensive Oral Evaluation (D0150) for a Limited Oral Evaluation (D0140) is over-coding.
- In another instance, you can’t bill Periodic Oral Evaluation (D0120) for a routine cleaning (prophylaxis, D1110).
- Moreover, you can’t bill a Consultation (D9310) in addition to the root canal procedure (D3340) on the same day after a general dentist has already made the diagnostic service.
2. 31% of errors involve radiologic images.
- “Unbundling” means billing multiple procedure codes for components of a single, comprehensive procedure that has its own specific code. Hence, the insurer pays multiple fees that add up to more rather than one fee for the radiologic image.
- Insufficient documentation means the patient’s clinical record does not provide sufficient evidence to justify the number and type of X-rays billed.
- Both can commonly misuse these CDT codes:
D0330: Panoramic radiographic image
D0210: Intraoral – complete series of radiographic images
D0230: Intraoral – periapical each additional radiographic image
D0272: Bitewings – two radiographic images
D0220: Intraoral – periapical first radiographic image
D0277: Vertical bitewings – 7 to 8 radiographic images
D0274: Bitewings – four radiographic images
D0270: Bitewings – single radiographic image
D0350: 3D photographic image
3. 17% of errors are due to missing elements on claims,
6. 32% of errors involve unbundling and/or insufficient documentation of procedures.
Why knowing these CDT costing mistakes matters
CDT codes are the language you use to communicate with insurance companies. Misusing this language can lead to a cascade of problems–the first and most significant being a hit on your financial health.
That’s why you need to get CDT coding right because it ensures the following:
As Albagmi et. al. put it into words, clinical coding “helps in the development of an administrative database utilized for reimbursement, financial reconciliation, audit, and research purposes.”
Revised CDT codes for 2026 that you need to know
For more information, please refer to The CDT 2026, the Coding Companion Kit, and the Consumer-Friendly CDT 2026: Plain Language Terms for Patient Communication, all available for purchase at ADAStore.org.
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Sources
Albagmi, S., Shawaheen, M., Asiri, E. M., & Alqadeer, T. A. (2023). Assessment of clinical miscoding errors and potential financial their implications on healthcare management – A case of local hospital in Najran, Saudi Arabia. Saudi Pharmaceutical Journal, 32(1), 101894.
https://doi.org/10.1016/j.jsps.2023.101894
Chandawarkar, R., Nadkarni, P., Barmash, E., Thomas, S., Capek, A., Casey, K., & Carradero, F. (2024). Revenue cycle management: The art and the science. Plastic and Reconstructive Surgery. Global Open, 12(7), e5756–e5756.
https://doi.org/10.1097/gox.0000000000005756
Dental Claims Case Study. (2024). Aapc.com.
https://www.aapc.com/resources/minimizing-errors-in-dental-claims-insights-from-an-aapc-audit?srsltid=AfmBOopX-C2CSTvQdjyO9khHqZirPNYB2ir82lxn1k2rQmwf7aPssQGL
Hospital double whammy: Less cash in, more cash out. (2022). Crowe RCA benchmarking analysis.
https://www.crowe.com/-/media/crowe/llp/widen-media-files-folder/h/hospital-double-whammy-less-cash-in-more-cash-out-chc2305-001b.pdf?rev=91d36c682ee744b1ab4bcb56cb769bc1&hash=9A63564E3DBD39914F3674540158857E
O’Reilly, K. (2025, May 20). Medical coding mistakes that could cost you. American Medical Association.
https://www.ama-assn.org/practice-management/cpt/medical-coding-mistakes-could-cost-you
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