CDT CODES, COVERAGE CATEGORIES & FREQUENCY (EXPANDED)

1. Most Common CDT Codes (Examples)

Exams: D0120, D0150, D0140
X-rays: D0274, D0330, D0220, D0210
Cleanings: D1110, D1120
Perio: D4341, D4342, D4910
Fillings: D2391–D2394
Crowns: D2740
Extractions: D7140

These codes help determine which coverage category applies.

2. Coverage Categories

Preventive
Exams, X-rays, cleanings — often covered at 100%.

Basic
Fillings, perio (SRP), simple extractions — typically 80%.

Major
Crowns, dentures, implants — often 50%.

Coverage determines how much insurance will pay.

3. Why Understanding Frequency Is Critical

Frequency determines WHEN a patient is eligible for a service.

Even if a service is “covered,” it does NOT mean it will be paid.

Examples:

• Cleanings: 2 per year / 1 every 6 months

• Fluoride: Once every 12 months

• Panoramic X-ray (D0330): Once every 3–5 years

• SRP: Once every 24–36 months

Why this matters:

• If a patient is not due, insurance pays $0

• The office must inform the patient of out-of-pocket cost

• Inaccurate frequency leads to denied claims

• Frequency affects scheduling and pre-authorizations

• It protects offices from incorrect treatment estimates

Understanding frequency is one of the MOST important skills in verification.