Mrn

MRN stands for Medical Record Number, a unique identifier assigned to an individual's health record by a healthcare facility. It is often referred to as a hospital number or patient identifier and is used to locate and link a person’s records across encounters, tests, procedures, billing, and scheduling within that institution.

The MRN is typically established at the first patient encounter and remains associated with that patient’s record within the facility’s system. Formats vary by institution and country, and MRNs can be numeric or alphanumeric. Because it is a form of protected health information, access to the MRN is restricted to authorized personnel. While MRN helps identify records, it is generally used in combination with other identifiers, such as name and date of birth, to verify a patient’s identity and prevent errors. Cross-institution information exchange often requires mapping or linking MRNs through a master patient index or health information exchange, as there is no universal, standardized national MRN.

In practice, MRNs can present limitations. A patient may receive different MRNs when registering at separate facilities, creating duplicates or fragmented records if systems are not interoperable. MRNs appear on specimen labels, patient wristbands, and within electronic health records and billing systems to ensure consistent record retrieval. Managing MRNs involves privacy considerations, accuracy in record linkage, and ongoing efforts to reduce duplicates and misidentification.

Beyond healthcare, MRN may have other meanings in different domains. This article focuses on the medical record number usage; see disambiguation for alternative definitions.