What does the term 'non-overlapping service' imply when using the XU modifier?

The term 'non-overlapping service' when using the XU modifier specifically indicates that the services do not occur at the same time. The XU modifier is utilized to demonstrate that the physician has performed a service that is distinct from other services provided on the same day, but it clarifies that there is no overlap in the time frame of the services being reported. This is particularly relevant when coding multiple services to ensure proper billing and to indicate that each service is separate and warranted, despite possibly being billed on the same date.

The other choices do not accurately define 'non-overlapping service.' While unrelated services may not be billed together, they don't necessarily imply anything about the timing of the services. Similarly, services occurring on different days would be covered through different billing practices, and the requirement for services to be performed on different patients is not connected to the concept of overlap or timing at all. Thus, the understanding of 'non-overlapping service' hinges on the timing of the service rather than these other factors.