Why are there different guidelines for inpatient versus outpatient coding? Hospitals have two patient types; outpatients and inpatients. There are different guidelines for each because of the difference in the types of services patients may receive. Inpatients are admitted to a hospital for treatment, while outpatients are seen without being admitted to the hospital. Coding for outpatients can include such services as laboratory, physical therapy, radiology, emergency room, same-day surgeries, or observation services. Coding for inpatients is usually more complex because they are typically sicker or undergoing more complex surgeries than those who are not admitted to a hospital. The procedure codes are the main difference between coding
