HCPCS Modifier RT

What modifier RT means

Modifier RT is a laterality modifier indicating a procedure was performed on the right side of a paired anatomic structure. It is informational and helps prevent duplicate-claim edits when the contralateral side is also reported.

When to use it

A procedure on a right-sided paired structure — for example, a right shoulder injection or a procedure on the right eye.

Documentation checklist

The record should support every item below before you append modifier RT.

• The right-side laterality noted in the procedure record
• The specific anatomic structure treated

Do NOT use modifier RT when

• A true bilateral procedure is performed — use modifier 50 (per the payer's bilateral rules)
• The structure is non-paired or midline
• The payer requires modifier 50 formatting instead of LT/RT

Common denial reasons

• RT/LT used where the payer expects modifier 50
• Laterality conflicts with the diagnosis (e.g., left-sided ICD-10 with RT)
• Duplicate edit when both sides are billed without distinct laterality lines

How to appeal a modifier RT denial

Confirm the laterality matches the diagnosis and resubmit with RT for the right-sided service; if the service was bilateral, verify whether the payer wants LT/RT on two lines or modifier 50 on one line and reformat the claim accordingly.

Payer notes

As with LT, bilateral formatting (LT + RT vs. modifier 50) varies by payer. LT/RT are commonly required on DMEPOS and imaging claims to document the side treated.

Related & commonly confused modifiers

Where modifier RT is used

• Surgery on paired structures
• Radiology
• Injections (e.g., 20610) and DMEPOS