When should a healthcare provider use the XU modifier?

The XU modifier is specifically designed to indicate that a service is unusual and does not overlap with other services provided. This modifier is used when a healthcare provider wants to ensure that a particular service is distinctly separate from another service, emphasizing that they do not share the same time or patient encounter context.

This is particularly relevant in cases where a provider needs to differentiate their service from similar procedures performed on the same day, thus clarifying for payers that the services are not merely duplicative but rather distinct and justifying separate reimbursement.

In contrast, the other options address scenarios where modifiers like the modifier 76 (for repeat services by the same provider) or modifiers related to multiple services (like the modifiers 59 and 91) would be more appropriate, as they pertain to situations of repeated services, separate documentation of related services, or multiple procedural services by different providers. The focus of XU is its role in highlighting the unusual nature and independence of the service being billed.