In simple words: This code is used when a patient receives emergency care in a hospital emergency room, even if the care continues for more than one day. It helps ensure that the hospital is paid correctly for these services, especially if the patient is also staying in a skilled nursing facility.

Modifier ET is used to indicate emergency services provided in a hospital emergency room (ER) setting, including those spanning multiple dates of service. It is used to bypass Skilled Nursing Facility (SNF) Consolidated Billing (CB) edits for ER services provided to patients in a Part A SNF stay. 

Example 1: A patient admitted to a skilled nursing facility experiences chest pain and is transferred to the hospital emergency room for evaluation and treatment. The ER services span two days. Modifier ET is appended to the ER service codes to ensure appropriate reimbursement and bypass SNF CB edits., A patient presents to the hospital emergency room with a severe laceration requiring sutures. The patient receives care in the ER over two consecutive days. Modifier ET is appended to applicable procedure codes., A patient residing in a skilled nursing facility requires emergency dental care for a broken tooth and associated pain and is taken to the hospital ER. The dentist provides the dental procedure in the hospital ER. The ET modifier can be appended to the appropriate dental procedure code.

Documentation should support the medical necessity of the emergency services provided in the ER setting. The record should clearly indicate the date(s) of service and the reason for the ER visit. For patients in a SNF, documentation linking the ER services to the SNF stay may be required.

** Modifier ET was introduced to address billing complexities for hospital emergency room services provided to patients in skilled nursing facilities, particularly when services span multiple dates. It facilitates accurate reimbursement by bypassing certain claim edits.