Which modifier is appended to services provided without the teaching physician's presence?

The correct answer highlights the importance of correctly indicating when certain requirements related to teaching physicians are not met. The modifier that is specifically used to indicate that a service was provided without the presence of a teaching physician is -GE. This modifier is utilized in scenarios where the teaching physician is not physically present during the service, which is a critical factor in determining billing and compliance in educational settings.

Using -GE informs payers that the service should be billed under the applicable guidelines for services performed without direct supervision, thereby ensuring proper reimbursement and adherence to Medicare regulations. This understanding is key, particularly in teaching hospitals or academic medical centers, where patient care may involve both residents and supervising physicians.

The other modifiers mentioned serve different purposes. For example, -Q6 indicates that a service is provided by a locum tenens physician, -25 is used to denote a significant, separately identifiable evaluation and management service performed on the same day as another procedure, and -GC indicates that the service was performed in part by a resident under the supervision of a teaching physician. Each of these modifiers has its specific context and application, distinct from what -GE covers.