What modifier must be appended when a resident is involved in the patient's care?

The appropriate modifier to append when a resident is involved in a patient’s care is the -GC modifier. The -GC modifier is used to indicate that the service was performed by a resident under the supervision of a teaching physician. This modifier helps to clarify the context of the service provided and ensures proper billing and reimbursement for the encounter.

When a teaching physician is supervising a resident's work, this modifier signals to payers that the teaching physician contributed to the service provided and meets the necessary guidelines for claiming that service. Proper documentation and application of this modifier ensure that educational activities meet compliance requirements, thus facilitating correct billing practices in educational settings.

Other modifiers mentioned, like -22, -25, and -24, serve different purposes. The -22 modifier indicates an increased procedural services, -25 signifies a significant, separately identifiable evaluation and management service provided on the same day as another procedure, and -24 indicates an unrelated evaluation and management service by the same physician during a postoperative period. Therefore, these modifiers do not apply in the context of resident involvement in patient care.