In simple words: This code is used when a service is provided at a hospital outpatient department that is not located on the main hospital campus.

A hospital facility appends modifier PO to a code for each service, procedure, or surgery that takes place at an off-campus location in a provider-based outpatient department. Off-campus means a location physically separate from the immediate area of the hospital facility and/or in a building located more than 250 yards away from the main hospital buildings. This is an informational modifier for data collection purposes. Individual providers should not append modifier PO and instead should use the appropriate place of service code to indicate outpatient services furnished in an on-campus, remote, or satellite location of a hospital or in an off-campus, provider-based hospital setting.

Example 1: A patient undergoes a colonoscopy at an off-campus, provider-based outpatient department of a hospital. The hospital would append modifier PO to the colonoscopy code., A patient receives chemotherapy at an off-campus, provider-based outpatient department of a hospital. Modifier PO is appended by the facility to the chemotherapy administration code., A patient has an MRI scan at a facility that is considered off-campus and provider-based. The hospital appends modifier PO to the MRI code.

Documentation should clearly indicate that the service was performed at an off-campus, provider-based outpatient department of a hospital.