HL7 Specification

Connectivity Options

We currently offer two connection options:

  • File drop: This is offered only for our Client-server practices.
  1. To establish a connection, we advise that the lab works with the practice IT company. We can provide you with the path to drop the files. Usually  :\gdb_common\OP Labs[insert lab facility name]\hl7.
  • TCP/IP via VPN: This is offered only for our Cloud practices.
  1. Our VPN Connectivity form will be provided.
  2. ´╗┐Port Selection can be assigned by us or the lab. If it is assigned by the outside vendor we will need to confirm this port is not already in use.

General Information

  • Office Practicum uses standard hl7 2.3.1 and 2.5.1 message formatting.
  • Messages should be sent as multi-message files or single message files with unique file names.
  • We prefer to have a file extension of ".hl7".

Performing Lab Information

  • The preferred method of sending this information is in an NTE segment following an OBX. If you need to display CLIA information then just add one more NTE segment in the end, for example:
NTE|1||Test Performed at:||NTE|2||Office Practicum Lab, 5  Walnut Grove Drive, Horsham; PA 19044|
NTE|3||CLIA  #:00A123456||
  • Or it can be sent in OBR 21.2 - 21.6.

Test Patient Demographics

For testing, we prefer to use one of the following test patients.

  • Mary Testpatient, DOB 5/16/1998, Female, Patient ID 99
  • John Testpatient, DOB 10/02/2008, Male, Patient ID 100

Textual Reports (Radiology, Transcriptions, Visit Summaries, etc.)

Note: Transcription may be sent with each line in its own NTE segment, or as repeated OBX-5 values with escape characters for formatting.


PDFs can be sent in one of two ways.

  • 2 of the same files- One file with the .HL7 file extension and the second file with .PDF file extension.
  • An encoded Base64 PDF can be sent in the HL7 file. This must be sent following the format listed below. The encoded PDF must be present in OBX 5.  

For example:

OBR|3|ZZ32458979^LAB|DA0999997|PDFReport1^PDF  Report^DIANON|||20100625000000|||||||||TUAEF01^UROPATHOLOGY^T^^^^^L||||||20100629123820|||F

Specification Details for HL7 2.3.1


Encoding charactersPlease utilize \|^~\&
MSH-04.1Sending Facility
MSH-06.1Receiving Facility will be the lab-issued practice ID or Account Number. Please use one unique ID per practice location, if possible.
MSH-07.1Date/Time of Message
MSH-09.1Message Type = ORU
MSH-09.2Trigger event
MSH-10Message Control ID (Unique value)


PID-02.1External ID
PID-03.1Internal ID
PID-05Pt. Name


PV1-7Attending Physician
  • 7.1: NPI # 
  • 7.2: Provider Last Name
  • 7.3: Provide First Name
  • 7.4: Provider middle name (if available)
  • 7.5: NPI


ORC-02.1Placer Order Number.ID, Order ID (Office Practicum will label this with our next available ID when the field is blank).
ORC-05Order Status, visible status for OP user.
ORC-12Ordering Provider
  • 12.1: Ordering Provider.ID (NPI#)
  • 12.2: Ordering Provider Last Name
  • 12.3: Ordering Provider First Name
  • 12.4: Ordering Provider middle name (if available)
  • 12.5: NPI


OBR-03.1Filler Order Number.ID, specimen ID (unique ID)
OBR-04Universal Service Identifier (Test ID)

If sending LOINC only, the total field needs to be 3 only in OBR-4 like the example below.

04.1-LOINC code


04.3-ID Type of LN

For example,


If sending local test id only, the total fields need to be 3 only in OBR-4 like the example below.

04.1-Local code


04.3-ID Type of L

For example,


If sending both LOINC and Local test id, the total fields need to be 6 only in OBR-4 like the example below.

04.1-LOINC code



04.4-Universal Service Identifier (Test ID)



For example,


OBR-07.1Observation (Sample Drawn)Date/Time: Collection Date
OBR-14Specimen Received Date/Time
OBR-16Ordering Provider
  • 16.1: Ordering Provider ID (NPI#)
  • 16.2: Ordering Provider last name
  • 16.3: Ordering Provider first name
  • 16.4: Ordering Provider middle name (if available)
  • 16.5: NPI
OBR-21Performing Lab Information can be sent in this field
  • 21.2: Lab Name
  • 21.3: Lab Address
  • 21.4: Lab City
  • 21.5: Lab State
  • 21.6: Lab zip code
OBR- 22.1Results Rpt Date/Time
OBR-25.1Result Status
OBR-28Copy to Provider
  • 28.1: NPI #                                                                                                                                                              
  • 28.2: Provider Last Name
  • 28.3: Provide First Name
  • 28.4: Provider middle name (if available)
  • 28.5: NPI


OBX-01Set ID
OBX-02Value Type
OBX-03Observation Identifier ID

If sending LOINC only, the total field needs to be 3 only in OBX-3 like the example below.

03.1-LOINC code


03.3-ID Type of LN

For example:


If sending Local Test ID only, the total fields need to be 3 only in OBX-3 like the example below.

03.1-Local code


03.3-ID Type of L

For example:


If sending both LOINC and Local Test ID, the total fields need to be 6 only in OBX-3 like the example below.

03.1-LOINC code


03.3-ID Type of LN

03.4-Local code


03.6-ID Type of L

For example:


OBX-05Observation Value
OBX-07Reference Range
  • Abnormal Flag
  • Sending entity must have the  ability to translate to HL7 Standard codes if the following are not used in outbound messages from internal systems:  
  • < = Below absolute low-off instrument scale
  • > = Above absolute high-off instrument scale
  • A = Abnormal (applies to non-numeric results)
  • AA = Very abnormal (applies to non-numeric units,  analogous to panic limits for numeric units)
  • B = Better--use when direction not relevant
  • D = Significant change down
  • H = Above high normal
  • HH = Above upper panic limits
  • I = Intermediate (microbiology sensitivities only)
  • L = Below low normal
  • LL = Below lower panic limits
  • MS = Moderately sensitive (microbiology sensitivities  only)
  • N = Normal (applies to non-numeric results)
  • null = No range defined, or normal ranges don't  apply
  • R = Resistant (microbiology sensitivities only)
  • S = Sensitive (microbiology sensitivities only)
  • U = Significant change up
  • VS = Very sensitive (microbiology sensitivities only)
  • W = Worse--use when direction not relevant
OBX-11Observation Result Status
OBX-14(Physiologically relevant) Date/Time of Observation
  • In the case of tests performed on specimens, the relevant date-time is the specimen’s collection date-time.
  • In the case of observations taken directly on the patient (e.g., X-ray images, history, and physical), the observation date-time is the date-time that the observation was performed.


NTE (after OBX)
  • Printable note following the result of preceding OBX.
  • Notes that need to display in front of the EMR User during result review, or that need to print are typically sent here.