What modifer do you use with cpt 99213?

When using CPT code 99213, the most common modifier is -25, which indicates that a significant, separately identifiable evaluation and management service was provided on the same day as another procedure or service. This modifier is essential when billing for a visit that includes both a problem-focused exam and additional services, ensuring that the E/M services are appropriately reimbursed. Other modifiers may be used depending on specific circumstances, but -25 is the primary one associated with 99213.