Which service would not typically be classified as an ancillary service?

Ancillary services are those that support the primary care or main treatment a patient receives. They are typically additional services that provide further diagnosis, treatment, or management of the patient's health condition.

Routine check-ups, on the other hand, are considered primary services since they are the main interactions between a patient and a healthcare provider focused on preventive care, monitoring of health status, and general wellness. These appointments are essential for patient health maintenance and disease prevention, making them a primary component of healthcare rather than a supportive or ancillary service.

In contrast, X-ray imaging, physical therapy, and rehabilitation programs are all services that provide supplemental care focused on diagnosis and recovery but are not the primary components of patient care. Therefore, routine check-ups stand apart as a fundamental aspect of healthcare delivery, distinguishing them from ancillary services.