How to Identify Hospital Claims for Emergency Room Visits in the Medicare Claims Data

Hospitals submit claims containing ER services on a CMS-1450 form (aka UB-04). Their claims containing ER charges will be found in the inpatient claims data (Inpatient file or MedPAR file) and the outpatient claims file.

Claims in the Outpatient and Inpatient files are identified via Revenue Center Code values of 0450-0459 (Emergency room) or 0981 (Professional fees-Emergency room).

Claims in the MedPAR file are identified via the Emergency Room Charge Amount field when the amount is > $0.

Although one can assume ER patients found in the inpatient data were admitted to the hospital, one cannot assume ER patients found in the outpatient data were not admitted to the hospital. Because some patients are transferred to a different hospital for admission and some hospitals bill ER and inpatient services separately, determining admission status for those ER visits found in the Outpatient file requires linking to the inpatient data to find evidence of an admission.

Please note charges for one ER visit will be found in either the Outpatient claims or the Inpatient claims; a visit will not generate ER charges on both an inpatient claim and an outpatient claim.

In summary, to find ER visits:

• Outpatient files:  Revenue Center Codes 0450-0459, 0981
• Inpatient files:  Revenue Center Codes 0450-0459, 0981
• Inpatient MedPAR: Emergency Room Charge Amount > $0

Note regarding LDS data: The MedPAR Hospital National LDS  file does not include a beneficiary-level identifier and cannot be linked to other data files, including the Outpatient SAF LDS. The Inpatient SAF LDS and Outpatient SAF LDS files are necessary to identify all ER visits that resulted in a hospital stay when working with the LDS data.  RIF MedPAR files do contain beneficiary identifiers and can be linked to other RIF claims files.