D4921 - Gingival Irrigation

Gingival irrigation with medicinal agent.

Procedure Code
D4921
Category
Periodontics

Insurance Verification Benchmarks & Billing Guidelines

Benchmark Policy Source: Delta Dental 2026

Frequency Limitation
Subject to group/individual contract frequency limitations (none)

Required Claim Attachments & Pre-Submission Checklist

  • Full-mouth periodontal charting with 6-point probing depths and bleeding points

Bill When (Allowable Clinical Criteria)

  • Indicated for medically and clinically necessary treatment as documented in patient's dental record.

Restrictions & Clinical Exclusions

  • When gingival irrigation is submitted as a standalone procedure, medicaments and solutions used for gingival irrigation are not covered benefits and the benefits are denied.
  • Fees for gingival irrigation are not billable to the patient when performed with any periodontal service.
  • Infection control is included in the fee for the dental services provided. Separate fees are not billable to the patient.
  • For benefit purposes, local anesthesia is an integral part of the periodontal procedures being performed and additional charges are not billable to the patient.
  • Laser disinfection is a technique, not a procedure. Fees for laser disinfection are not billable to the patient.
  • Benefits for laser disinfection as a standalone procedure are denied as investigational.

Common Claim Denial Codes & Overturn Strategies

Denial CodeDenial ReasonAppeal & Overturn Strategy
CO-119Benefit maximum or frequency limitation exceeded for procedureSubmit clinical narrative detailing extraordinary circumstances, active recurrent pathology, or exception criteria.

ICD-10 Justification & Crosswalk Mappings

ICD-10 CodeDiagnosis NameCategoryPrimary JustificationClaim TypeClinical Scenario