The following rules apply:
* Modifier 24 is applied to only two possible code sets: evaluation and management (E/M) services (99201-99499) or general ophthalmological services (92002-92014), which are eye examination codes.
* Modifier 24 is not valid with surgical procedures, labs, x-rays, or supply codes.
* The new E/M service or eye exam usually involves a different diagnosis, but not always. For example, the same diagnosis as the original procedure could be used for the new E/M if the problem occurs at a different anatomical site.
* Modifier 24 is not used to report exams performed for routine postoperative care.
* Modifier 24 is an information modifier.
Dr. Smith sees an established patient in his office who had a bike accident. Dr. Smith performs an intermediate repair for a 4.0cm wound on the patient’s forehead. The repair has a 10-day global period. Three days later, the patient sees Dr. Smith complaining about sinus trouble. Dr. Smith performs a problem focused exam and diagnoses the patient with a sinus infection. He writes a prescription and codes the visit as a 99212-24.