What is the purpose of CPT modifiers in medical billing?

• A. They replace CPT codes when missing
• B. They provide additional information about procedures to adjust payment or indicate special circumstances
• C. They determine patient eligibility
• D. They authorize prior approvals

Answer: (B)

Modifying CPT codes is about adding extra information to the service to explain why payment might differ or to flag special circumstances. This is exactly what CPT modifiers do: they accompany a procedure code to adjust reimbursement or to indicate something notable about how the service was performed. They don’t replace missing codes, they don’t determine patient eligibility, and they don’t authorize prior approvals. For instance, a professional versus a technical component, a bilateral procedure, or a procedure performed in a different setting may use modifiers to show the payer the specific context, which can change how the service is paid.