Modifier LT- Left Side

Modifier LT is used to identify a procedure performed on the left side of the body.

What is Modifier LT?

Modifier LT tells insurance payers that a service or procedure was performed on the patient’s left side.

When to Use Modifier LT

• A procedure is performed on the left side
• Laterality must be identified
• The payer requires side-specific billing
• Documentation supports left-side treatment

Billing Example

A provider performs a procedure on the patient’s left knee. Modifier LT may be appended to the procedure code to identify the left side.

Documentation Tips

• Clearly document left-side location
• Match the modifier to the medical record
• Avoid using LT when laterality is not required
• Confirm payer-specific billing requirements

Common Denial Reasons

• Laterality missing from documentation
• Modifier does not match provider notes
• Incorrect side reported
• Modifier not required for the service

Related Modifiers

Modifier RT

Modifier XS

Modifier 59

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