Modifier GG- Performance and Payment of a Screening Mammogram and Diagnostic Mammogram on the Same Patient, Same Day

Modifier GG is used when both a screening mammogram and diagnostic mammogram are performed on the same patient on the same day.

What is Modifier GG?

Modifier GG tells insurance payers that a screening mammogram and diagnostic mammogram were both performed during the same encounter.

When to Use Modifier GG

• A screening mammogram is performed
• A diagnostic mammogram is also required
• Both services occur on the same day
• Documentation supports both services

Billing Example

A patient presents for a screening mammogram. During the screening, an abnormal finding requires additional diagnostic imaging on the same day. Modifier GG may be appended as appropriate.

Documentation Tips

• Document both mammogram services
• Include screening findings
• Support diagnostic medical necessity
• Maintain complete imaging records

Common Denial Reasons

• Missing documentation
• Unsupported diagnostic imaging
• Incorrect modifier usage
• Incomplete medical records

Related Modifiers

Modifier GX

Modifier GA

Modifier GY

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