D1110 & D4910 – Avoid Common Dental Code Errors

December 14, 2023

Updated 2/17/26

Every January, the dental world braces for new CDT codes, and in January 2026, another 31 are joining the 2026 CDT Code lineup. That means over 800 active codes your team needs to navigate flawlessly.

For most dental billers, it’s not just overwhelming–it’s exhausting. One coding slip can mean a denied claim, a confused patient, and lost revenue.

One of the most common culprits?

Confusion about when to report D1110 (Adult Prophylaxis) and D4910 (Periodontal Maintenance).

What is Dental Code D1110?

Removal of Local Irritational Factors

D1110 is used to report the removal of local irritational factors for patients with mixed and permanent dentition. It is generally performed on patients with healthy gums and no history of periodontal disease; however, it is not a statement of health and may also be performed as an adjunct to periodontal maintenance (see the Q&A below).

Bill D1110 when:

• The patient has permanent teeth and no active periodontal disease.
• The visit is preventive, not therapeutic.
• The goal is to maintain oral health — not treat infection or inflammation.

If the patient has moderate to severe gingivitis with bleeding on probing on more than 30% of teeth and no bone loss, use Dental Code D4346 instead.

What is Dental Code D4910?

The Lifelong Fight Against Periodontal Disease

D4910 is not a standard cleaning. It’s atherapeutic procedure; maintenance therapy for patients who’ve already undergone treatment for periodontal disease. It’s defined by the ADA as:

“This procedure is instituted following periodontal therapy and continues at varying intervals, determined by the clinical evaluation of the dentist, for the life of the dentition or an implant replacement. It includes removal of the bacterial plaque and calculus from supragingival and subgingival regions, site specific scaling and root planing where indicated, and polishing the teeth. If new or recurring periodontal disease appears, additional diagnostic and treatment procedures must be considered.”

Bill D4910 when:

• The patient has had scaling and root planing (SRP) or osseous surgery.
• You perform prophylaxis plus selective scaling and root planing, where indicated.
• You’re maintaining the results of prior periodontal therapy.

While the ADA states that maintenance should continue “for life,” insurers often limit the number or duration of covered visits, so verify plan details every time. Include dates and treated quadrants of previous periodontal procedures in the narrative.

Maximize reimbursement with a narrative:

“If benefits are not available for D4910, please pay the alternate benefit of D1110.”

That way, you report the correct procedure and still help the patient maximize their benefits.

FAQs about D1110 and D4910

Q: If D4341 or D4342 is done on two or more quadrants, does that mean D4910 should be coded moving forward? What if SRP was done on fewer than two quadrants? Should we stick with D1110?

A: Excellent question, and one that trips up many practices. While some payors won’t reimburse D4910 after treating just one quadrant, or even two D4342 quadrants, remember this golden rule:

Always code for what you do – not what you think will get reimbursed.

If the procedure meets all D4910 clinical criteria, it should be coded as such. That includes polishing, supragingival and subgingival plaque/calculus removal, and site-specific SRP as needed.

If only a few isolated sites were treated, D111) prophylaxis might be more appropriate. There’s nothing in CDT language that prevents its use; it’s up to the clinician’s judgment.

Q: If a patient has had SRP, does that mean future hygiene treatments are limited only to D4910?

A: While D4910 periodontal maintenance is appropriate for a patient who has had SRP or perio surgery “for the life of the dentition and any implant replacements,” that does NOT mean they can never have a prophylaxis again. A prophylaxis is NOT A STATEMENT OF HEALTH.

Per the 2026 ADA Coding Companion: “There is nothing in the codes’ D4910, D1110, or D1120 nomenclatures or descriptors that makes these procedures mutually exclusive. If the dentist determines that the patient’s periodontal health can be augmented with periodic routine prophylaxis procedures (removal of plaque, calculus, and stains from the tooth structures for the purpose of controlling local irritational factors), then this service should be performed and reported as D1110 or D1120, depending on the state of the dentition.”

While prophylaxis is not therapeutic (does not treat disease), it may still be used as a supplement or adjunct to therapeutic treatments. That said, if you perform subgingival scaling and site-specific SRP, you should report D4910 regardless of insurance reimbursement. You may, however, include a narrative that states, “If benefits are exhausted for D4910, please pay the alternate benefit of D1110.” That way, you still “code for what you do,” but may still receive some reimbursement if allowed by the plan document language.

Get the Help Your Practice Deserves

At eAssist, our team of Success Consultants understands the importance of CDT code accuracy and claim compliance. We help dental teams avoid coding errors,  minimize denials, and collect what is rightfully owed. Schedule a consultation and learn how eAssist can help your practice thrive.

Disclaimer: Insurance administration and dental billing recommendations presented here represent the opinions of the author or our staff and are for informational purposes only. You are responsible for your own use of the CDT Codes, insurance administration, and dental billing. For the latest CDT codes and official interpretations, contact the American Dental Association or visit ADA.org.