MFN^M01 — Master File Notification (generic)

How do you sync the physician master file between HIS and EHR? The service catalog between PMS and billing? MFN^M01 is the generic HL7 v2 message that notifies a master-file update.

Purpose

M01 is the generic variant of the MFN family: notification of an arbitrary master-file update. The target file is set in MFI-1 (Master File Identifier — table 0175). M02, M03, M04... are typed variants (physicians, locations, codes...) that reuse the same structure but are preferable when the file is known.

Most frequently MFN-synced master files:

• STF — Staff Master File (physicians, nurses, technicians).
• LOC — Location Master File (rooms, wards, halls).
• CHM — Charge Master (billing catalog).
• CDM — Charge Description Master.
• OM1-OM6 — Observation Master Files (battery, items, dictionaries).
• OMM — Test/Observation Master (LIS dictionary).

Segment structure

MFN_M01
  MSH                    Message Header (mandatory)
  [ SFT ]                Software Segment (optional)
  MFI                    Master File Identification (mandatory)
  { MFE                  Master File Entry (mandatory, repeating)
    <Z..>                File-specific Z segment (STF, LOC, OMx, etc.)
  }

MSH — Message Header

Standard: MSH-9 = MFN^M01^MFN_M01, MSH-12 = 2.5.1. Often NE on application ACK (the receiver answers with MFK immediately).

MFI — Master File Identification

• MFI-1: master file identifier (table 0175). E.g. STF for Staff, LOC for Location, CHM for Charge.
• MFI-2: file application identifier.
• MFI-3: file event type (UPD=Update, REP=Replace, HDR=Header).
• MFI-4: effective date (CCYYMMDDHHMMSS).
• MFI-5: file last-modified date.
• MFI-6: expected response indicator (NE=Never, AL=Always).

MFE — Master File Entry

• MFE-1: entry action code (table 0180: MAD=Add, MUP=Update, MDC=Deactivate, MDL=Delete).
• MFE-2: unique entry identifier (sender-side).
• MFE-3: receiver-side identifier (if already mapped).
• MFE-4: entry effective date.
• MFE-5: entry primary key (varies per file).

MFR — Master File Response (ack)

The receiver returns an MFK^M01^MFK_M01:

• MFK = Master File ACK with MSA (Application Accept/Error/Reject).
• MFA = Master File ACK details, one per MFE entry (partial success possible).

Real-world example

Notification of Dr Smith (cardiologist) added to the STF master file, sent by the reference system REF@HOSP01 to EHR@CLINIC02:

MSH|^~\&|REF|HOSP01|EHR|CLINIC02|20260514110000||MFN^M01^MFN_M01|MSG00000050|P|2.5.1|||AL|NE
MFI|STF|^L^^^MFI|UPD|20260514110000|20260514110000|NE
MFE|MAD|||20260514110000|DRSMITH^Smith^James^A^^DR.^MD^^^^^^^XYZ
STF|DRSMITH|DRSMITH^Smith^James^A^^DR.|Dr.|D^M.D.^L|S^Staff|MED|||M|19710403|CIV|JONES|||||+1-555-555-7890|cardio^Cardiology
PRA|DRSMITH^Smith^James^A^^DR.|HOSP01|CARD|||I|CARD&Cardiology^L|MD|NPI1234567890|DEA12345

• MSH: sent from REF@HOSP01 to EHR@CLINIC02, MFN^M01, 2.5.1.
• MFI: STF file (Staff), action UPD (incremental update), effective date 14 May 2026 11:00.
• MFE: code MAD (Add), new entry for DRSMITH on 14 May 2026.
• STF: staff details — Dr Smith, MD, Medical, Staff type, sex M, born 3 April 1971, contact +1-555-555-7890, cardio Cardiology service.
• PRA: practice privileges — department CARD, NPI 1234567890, DEA 12345.

MFN events

Common errors

• Misused MFI-3: REP (Replace) overwrites the WHOLE file, UPD applies deltas. Use REP only at initialisation.
• MFE without primary key (MFE-2 or MFE-5): the receiver doesn't know which entry to update.
• MAD on existing entry: receiver may either create a duplicate or reject depending on its logic. Use MUP for updates.
• MDL without downstream handling: deleting a physician from the STF on the HIS side without managing references in existing Encounters and Orders breaks referential integrity.
• Batch without throttling: sending a large MFN without pause or intermediate acknowledgment can saturate the receiver.

See also: ADT^A01 which typically consumes STF master-file codes, and ADT^A08 for patient demographic updates (vs MFN which updates the reference data).