Select the modifier for an unrelated procedure.

The modifier designated for an unrelated procedure is the -79 modifier. This modifier is specifically used to indicate that a procedure or service is performed on the same day as another procedure but is unrelated to it. It helps to clarify the medical necessity and rationale for performing the second procedure, ensuring that both services are accurately reported and reimbursed.

When using the -79 modifier, it is essential to demonstrate that the procedures are distinct, which is crucial for proper coding and billing practices. This approach allows for transparency in the patient's medical record, indicating to insurers and payers that the procedures, while occurring on the same day, address different conditions or issues.

The other modifiers listed are used for different circumstances; for instance, -25 indicates a significant, separately identifiable evaluation and management service performed on the same day as a procedure, which is not the same context as unrelated procedures. Similarly, -50 is used for bilateral procedures, and -58 signifies a staged or planned procedure performed during the postoperative period. Each of these modifiers serves its own unique purpose in coding and billing, but when identifying an unrelated procedure, -79 is the correct choice.