What does the modifier XU represent?

The modifier XU represents "Unusual Non-Overlapping Service." This modifier falls under a subset of modifiers known as the "X" modifiers, which provide additional specificity to certain services rendered during a patient encounter. The XU modifier is specifically used to indicate that a service is distinct or unusual in its application and does not overlap with other services performed on the same day or during a specific episode of care. This can help clarify billing and ensure appropriate reimbursement when multiple services are provided that might otherwise be considered bundled.

Using XU allows healthcare providers to provide necessary context to insurance payers, helping to avoid claim denials associated with services that may otherwise be expected to overlap in coding. The proper use of this modifier supports the accuracy of the medical record and the justification for each distinct service rendered.

In contrast, the other options do not accurately reflect the function of the XU modifier, as they either misinterpret the terminology or do not exist in standard CPT usage related to modifiers.