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HL7 resources

HL7 PID Segment

doctor talking with patient

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.

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The fields in the PID segment are as follows:

14SIO Set ID – Patient ID
220CXO Patient ID (External ID)
320CXRYPatient ID (Internal ID)
420CXOYAlternate Patient ID – PID
548XPNRYPatient Name
648XPNO Mother’s Maiden Name
726TSO Date/Time of Birth
81ISO Sex
948XPNOYPatient Alias
101ISO Race
11106XADOYPatient Address
124ISB Country Code
1340XTNOYPhone Number – Home
1440XTNOYPhone Number – Business
1560CEO Primary Language
161ISO Marital Status
173ISO Religion
1820CXO Patient Account Number
1916STO SSN Number – Patient
2025DLNO Driver’s License Number – Patient
2120CXOYMother’s Identifier
223ISO Ethnic Group
2360STO Birth Place
242IDO Multiple Birth Indicator
252NMO Birth Order
2760CEO Veterans Military Status
2880CEO Nationality
2926TSO Patient Death Date and Time
301IDO 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:



PID|||PATID1234^5^M11||JONES^WILLIAM^A^III||19610615|M-||C|1200 N ELM





AL1|1||^Penicillin||Produces hives

AL1|2||^Cat dander|Respiratory distress

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