PID — Patient Identification
Appears in ADT messages, ORM orders, ORU results, SIU scheduling, and most other message types that reference a patient.
The PID segment contains the primary patient identification information including name, date of birth, address, and medical record numbers. It is the cornerstone of patient identity in HL7 v2.x messages and appears in virtually every ADT, order, and result message.
Real-World Context
PID is where most MPI (Master Patient Index) issues surface. The three-way combination of PID.3 (patient identifier list), PID.5 (patient name), and PID.7 (date of birth) is your primary identity verification triplet. When downstream systems create duplicate patients, the root cause is almost always inconsistent or missing identifiers in PID.3 — especially missing assigning authority values.
Field Reference
Click any row to see the full description, common values, and troubleshooting tip.
| # | Field Name | Type | Req | Max Len | |
|---|---|---|---|---|---|
| 1 | Set ID - PID | SI | O | 4 | ▶ |
| 2 | Patient ID (External) | CX | O | 20 | ▶ |
| 3 | Patient Identifier List | CX | R | 250 | ▶ |
| 4 | Alternate Patient ID | CX | O | 20 | ▶ |
| 5 | Patient Name | XPN | R | 250 | ▶ |
| 6 | Mother's Maiden Name | XPN | O | 250 | ▶ |
| 7 | Date/Time of Birth | TS | O | 26 | ▶ |
| 8 | Administrative Sex | IS | O | 1 | ▶ |
| 9 | Patient Alias | XPN | O | 250 | ▶ |
| 10 | Race | CE | O | 250 | ▶ |
| 11 | Patient Address | XAD | O | 250 | ▶ |
| 12 | County Code | IS | O | 4 | ▶ |
| 13 | Phone Number - Home | XTN | O | 250 | ▶ |
| 14 | Phone Number - Business | XTN | O | 250 | ▶ |
| 15 | Primary Language | CE | O | 250 | ▶ |
| 16 | Marital Status | CE | O | 250 | ▶ |
| 17 | Religion | CE | O | 250 | ▶ |
| 18 | Patient Account Number | CX | O | 250 | ▶ |
| 19 | SSN Number - Patient | ST | O | 16 | ▶ |
| 20 | Driver's License Number | DLN | O | 25 | ▶ |
| 21 | Mother's Identifier | CX | O | 250 | ▶ |
| 22 | Ethnic Group | CE | O | 250 | ▶ |
| 23 | Birth Place | ST | O | 250 | ▶ |
| 24 | Multiple Birth Indicator | ID | O | 1 | ▶ |
| 25 | Birth Order | NM | O | 2 | ▶ |
| 26 | Citizenship | CE | O | 250 | ▶ |
| 27 | Veterans Military Status | CE | O | 250 | ▶ |
| 28 | Nationality | CE | O | 250 | ▶ |
| 29 | Patient Death Date and Time | TS | O | 26 | ▶ |
| 30 | Patient Death Indicator | ID | O | 1 | ▶ |
| 31 | Identity Unknown Indicator | ID | O | 1 | ▶ |
| 32 | Identity Reliability Code | IS | O | 20 | ▶ |
| 33 | Last Update Date/Time | TS | O | 26 | ▶ |
| 34 | Last Update Facility | HD | O | 241 | ▶ |
| 35 | Taxonomic Classification Code | CE | O | 250 | ▶ |
| 36 | Breed Code | CE | O | 250 | ▶ |
| 37 | Strain | ST | O | 80 | ▶ |
| 38 | Production Class Code | CE | O | 250 | ▶ |
| 39 | Tribal Citizenship | CWE | O | 705 | ▶ |
Example Segment
1PID||1||123456^^^HOSPITAL^MR~987654321^^^&2.16.840.1.113883.4.1&ISO^SS||DOE^JOHN^A^^^||19850315|M||2106-3^White^HL70005|123 Main St^^Springfield^IL^62701^USA^H|||(217)555-1234|||M|||ACCT001^^^HOSPITAL^AN|123-45-6789
Related Segments
Used In Message Types
Parse messages with PID in real time
Paste any HL7 message into our free viewer. Decodes every segment and field instantly, client-side.
Open HL7 Message Viewer →Need HL7 mapping templates?
The HL7 Integration Toolkit includes field mapping worksheets, interface spec templates, and a go-live checklist for every major HL7 message type.
View HL7 Integration Toolkit →