In Part 1 of our Modifier 58 series, KZA Coding Expert Rebecca Mizelle walks us through the fundamentals of this staged or related procedure modifier, using content prepared by KZA Coding Expert Christine Banks. Learn the three distinct circumstances in which Modifier 58 may apply, how it differs from Modifiers 78 and 79, and what it communicates to the payer during an active global period. We also cover reimbursement, when a new global period begins, and why distinguishing a planned or expected course of care from a postoperative complication is critical for both accurate payment and compliance.