The HL7 PID segment is found in every type of ADT message (i.e. ADT-A01, ADT-A08, etc.) and contains 30 different fields with values ranging from patient ID number, to patient sex, to address, to marital status, to citizenship. The PID segment provides important identification information about the patient and, in fact, is used as the primary means of communicating the identifying and demographic information about a patient between systems. Due to the nature of the information found in the PID segment, it is unlikely to change frequently.
The fields in the PID segment are as follows:
| SEQ | LEN | DT | OPT | RP/# | ELEMENT NAME |
| 1 | 4 | SI | O | Set ID – Patient ID | |
| 2 | 20 | CX | O | Patient ID (External ID) | |
| 3 | 20 | CX | R | Y | Patient ID (Internal ID) |
| 4 | 20 | CX | O | Y | Alternate Patient ID – PID |
| 5 | 48 | XPN | R | Y | Patient Name |
| 6 | 48 | XPN | O | Mother’s Maiden Name | |
| 7 | 26 | TS | O | Date/Time of Birth | |
| 8 | 1 | IS | O | Sex | |
| 9 | 48 | XPN | O | Y | Patient Alias |
| 10 | 1 | IS | O | Race | |
| 11 | 106 | XAD | O | Y | Patient Address |
| 12 | 4 | IS | B | Country Code | |
| 13 | 40 | XTN | O | Y | Phone Number – Home |
| 14 | 40 | XTN | O | Y | Phone Number – Business |
| 15 | 60 | CE | O | Primary Language | |
| 16 | 1 | IS | O | Marital Status | |
| 17 | 3 | IS | O | Religion | |
| 18 | 20 | CX | O | Patient Account Number | |
| 19 | 16 | ST | O | SSN Number – Patient | |
| 20 | 25 | DLN | O | Driver’s License Number - Patient | |
| 21 | 20 | CX | O | Y | Mother’s Identifier |
| 22 | 3 | IS | O | Ethnic Group | |
| 23 | 60 | ST | O | Birth Place | |
| 24 | 2 | ID | O | Multiple Birth Indicator | |
| 25 | 2 | NM | O | Birth Order | |
| 26 | 4 | IS | O | Y | Citizenship |
| 27 | 60 | CE | O | Veterans Military Status | |
| 28 | 80 | CE | O | Nationality | |
| 29 | 26 | TS | O | Patient Death Date and Time | |
| 30 | 1 | ID | O | Patient Death Indicator |
*Note: For the complete HL7 Standard, please go to the HL7 organization website.
The HL7 standard allows for several different types of patient identification numbers in the first four fields of the PID segment. The differences are described below:
- PID-1: Set ID – Patient ID – a number to identify the transaction
- PID-2: Patient ID (External ID) – the patient identifier number used by one or more outside institutions (i.e. a physician’s office that is referring the patient)
- PID-3: Patient ID (Internal ID) – the primary, unique patient identifier number used by the facility
- PID-4: Alternate Patient ID – an alternate, additional, temporary or pending patient identification number
In HL7 pipe and hat format, the PID segment (shown in red) for an ADT-A01 message would look like this:
MSH|^~\&|ADT1|MCM|LABADT|MCM|198808181126|SECURITY|ADT^A01|MSG00001-|P|2.3
EVN|A01|198808181123
PID|||PATID1234^5^M11||JONES^WILLIAM^A^III||19610615|M-||C|1200 N ELM
STREET^^GREENSBORO^NC^27401-1020|GL|(91-9)379-1212|(919)271-
3434||S||PATID12345001^2^M10|123456789|9-87654^NC
NK1|1|JONES^BARBARA^K|WIFE||||||NK
PV1|1|I|2000^2012^01||||004777^LEBAUER^SIDNEY^J.|||SUR||-||ADM|A0-
AL1|1||^Penicillin||Produces hives
AL1|2||^Cat dander|Respiratory distress