HL7 MFR_M01 (Master Files Query Response) | Integration Soup HL7 Reference Guide

HL7 MFR_M01 Master Files Query Response

The older response carrying records found by an MFQ query.

HL7 message structure MFR_M01 groups and segments from HL7 v2.5.1 Hide structure

These are the generated groups and segments for the version selected at the top of the page. The article explains the workflow, and this panel follows the chosen HL7 version.

Message Structure

Segment	Name	Required	Repeatable
MSH	Message Header	Yes	No
SFT	Software Segment	No	Yes
MSA	Message Acknowledgment	Yes	No
ERR	Error	No	Yes
QAK	Query Acknowledgment	No	No
QRD	Original-Style Query Definition	Yes	No
QRF	Original style query filter	No	No
MFI	Master File Identification	Yes	No
MFR_M01.MF_QUERY	Mf Query group	Yes	Yes
MFE	Master File Entry	Yes	No
anyHL7Segment	Anyhl7segment group	Yes	No
DSC	Continuation Pointer	No	No

MFR_M01 returns master-file records after an MFQ_M01 query. It echoes the query, identifies the master file, then repeats returned entries using MFE plus the segment that contains the actual record data.

Like MFQ, this is a legacy pattern. It is still useful to document because older catalog and reference-data interfaces often live for a long time, quietly feeding systems that everyone relies on.

A small MFR M01 example

MSH|^~\&|CATALOG|CITYHOSP|LIS|CITYHOSP|20260718121003||MFR^M01^MFR_M01|MFR010001|P|2.5.1 MSA|AA|MFQ010001 QAK|MFQ010001|OK QRD|20260718121000|R|I|MFQ010001|||10^RD|LABTEST^Laboratory test master^HL70175|MFN|CATALOG QRF|CATALOG|20260701000000|20260718235959|CBC^Complete blood count^L MFI|LABTEST^Laboratory test master^HL70175|CATALOG^CITYHOSP|REP|20260718121003|20260718121003|AL MFE|MAD|MFR010001|20260718121003|CBC^Complete blood count^L|CE OM1|1|CBC^Complete blood count^L|NM~ST|Y|LAB^City Hospital Laboratory^L|Complete blood count panel DSC|END|I

What workflow it represents

The receiver is answering a catalog or reference-data query. The requester may use the returned record to populate a local cache, validate a code, or display current catalog metadata.

Because the response can be partial, the consumer should read query status, returned records, and continuation together. A successful response with continuation is not the same thing as a complete catalog.

How to read the structure

MSH and MSA frame the response. QAK reports query status when present. QRD and QRF echo the old-style query.

MFI identifies the master file being returned. Each response group starts with MFE and then carries one actual master-file record segment, such as OM1 for a test/observation definition. DSC handles continuation.

Implementation traps

Do not ignore QAK or DSC. A response can be accepted, partial, empty, or continued, and each state should drive a different cache/update decision.

Also keep the primary key from MFE with the returned record. If the receiver changes the display text but the primary key is the stable identifier, mapping by display text will eventually hurt.

Reference notes

HL7 v2+ master-file material describes MFQ/MFR as withdrawn in later versions, but local v2.5.1 data still defines MFR_M01 with MSA, optional QAK, QRD/QRF, MFI, returned MFE groups, and DSC continuation.