In simple words: This code is used when you receive a service or item, like medicine or bandages, at a hospital emergency room that's not attached to the main hospital building.

Modifier ER denotes that an item or outpatient hospital service was provided by an off-campus provider-based emergency department. "Off-campus" refers to a location physically separate from the immediate area of the hospital facility, typically in a building located more than 250 yards away from the main hospital buildings. This modifier is used for informational purposes and does not impact payment (as of 2024). Individual providers should not append modifier ER. Instead, they 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 receives stitches in a provider-based, off-campus emergency department for a laceration on their hand. The HCPCS code for the sutures would be appended with the ER modifier., A patient receives pain medication in a provider-based, off-campus emergency department for a migraine. The HCPCS code for the medication would be appended with the ER modifier., A patient receives an X-ray in a provider-based, off-campus emergency department for a suspected fracture. The HCPCS code for the X-ray would be appended with the ER modifier.

Documentation should clearly indicate that the service or item was furnished in an off-campus, provider-based emergency department of a hospital.

** Critical access hospitals (CAHs) are not required to append this modifier. As of December 2024, it's important to verify the latest information on the usage and potential payment implications of the ER modifier.