Final answer:
The modifier used to indicate an E&M service that is unrelated to the global service is modifier 24. It is crucial to use this modifier correctly to ensure proper reimbursement and to have clear documentation that the service is for a reason not associated with the global procedure.
Step-by-step explanation:
The modifier used to indicate that an E&M (Evaluation and Management) service is unrelated to the global service provided is modifier 24. Modifier 24 is specifically used on E&M services that are provided on the same day or in the global period of a previous procedure but are for a different reason not related to the original procedure.
It's important to correctly use this modifier to ensure that the healthcare provider is properly reimbursed for the distinct service. Improper use can lead to claim rejections or denials, so clear documentation of the rationale for the service's independence from the global procedure is essential.
There are other modifiers like 25, 59, and 79, which have different applications. For example, modifier 25 indicates that on the day of a procedure, a significant, separately identifiable E&M service was performed, while 59 is used to signify a distinct procedural service, and 79 indicates an unrelated procedure or service by the same physician during the post-operative period.