Understanding Dental Code D2520

When to Use D2520 dental code

The D2520 dental code is used to report an inlay—specifically, a metallic inlay that covers two surfaces of a tooth. Inlays are indirect restorations fabricated outside the mouth and then cemented into place, typically when a tooth has too much damage for a filling but not enough for a full crown. Use D2520 when the restoration is limited to two surfaces and is made of a metallic material, such as gold or a noble alloy. This code should not be used for ceramic or resin-based inlays, which have their own distinct CDT codes. Accurate code selection ensures proper reimbursement and compliance with insurance requirements.

Documentation and Clinical Scenarios

Proper documentation is critical for successful claims involving D2520. Clinical notes should clearly describe the extent of decay or fracture, the surfaces involved, and the rationale for choosing a metallic inlay over other restorative options. Include pre-operative radiographs, intraoral photographs, and a detailed narrative explaining why a direct restoration (like a filling) was not feasible. Common clinical scenarios for D2520 include:

• Extensive caries or fractures affecting two surfaces but with sufficient tooth structure remaining.
• Replacement of a failed two-surface metallic inlay.
• Patients with a history of failed direct restorations in the same area.

Be sure to differentiate D2520 from related codes, such as D2510 (one-surface metallic inlay) and D2530 (three or more surfaces).

Insurance Billing Tips

To maximize reimbursement and minimize denials for D2520, follow these best practices:

• Verify coverage: Before treatment, check the patient’s benefits for inlays, as some plans downgrade inlays to fillings or have frequency limitations.
• Submit complete documentation: Attach pre-op and post-op radiographs, intraoral images, and a narrative explaining the need for an indirect restoration.
• Use accurate CDT codes: Ensure D2520 is only used for two-surface metallic inlays. Incorrect coding can lead to claim denials or audits.
• Track EOBs and AR: Monitor Explanation of Benefits (EOBs) for downgrades or partial payments. If the claim is underpaid or denied, review the payer’s policy and submit a timely appeal with additional supporting documentation.

Clear communication with patients about their financial responsibility is also essential, as insurance may not cover the full fee for inlays.

Example Case for D2520

Case: A patient presents with a fractured MOD (mesio-occluso-distal) amalgam restoration on tooth #19. The dentist determines that a direct filling would not provide sufficient strength due to the extent of the damage, but a full crown is not necessary. After discussing options, the patient elects a two-surface metallic inlay.

Billing workflow:

1. Insurance is verified, confirming coverage for metallic inlays with a frequency limitation of once every five years.
2. Clinical notes detail the fracture, surfaces involved, and rationale for an inlay. Pre-op radiographs and intraoral photos are taken.
3. The claim is submitted with D2520, supporting images, and a narrative.
4. The EOB returns with a downgrade to a two-surface amalgam filling. The office reviews the policy, confirms the downgrade clause, and informs the patient of the difference in coverage.

This example highlights the importance of documentation, insurance verification, and proactive communication for successful billing of D2520.