HL7 v2 Reference

HL7 v2 NK1-2 (Name): Format, Values, and Testing Notes

Jul 27, 2026 · 4 min read

A next-of-kin record with only a family name and no given name is valid HL7 — and it's exactly the kind of input that crashes a display screen built assuming a first and last name always show up.

Quick answer

NK1-2 holds the associated party's name using the same extended person name (XPN) component structure as the patient name field, PID-5: family name, given name, middle name, suffix, prefix, and so on, separated by carets. Unlike PID-5, it's common for NK1-2 to arrive with several components blank.

What this field contains

Component 1

Family Name — the contact's last name; often the only component reliably populated

Component 2

Given Name — first name; frequently missing for informally captured emergency contacts

Component 3

Middle Name/Initial — optional middle name or initial

Component 5

Suffix — Jr., Sr., III, etc., rarely populated but occasionally present for guarantor records

Example

Synthetic example Generated by Synthibase

NK1|1|DOE^JANE^M|SPO|482 OAK ST^^DENVER^CO^80202|3035550142|||EC

Here the contact's name is DOE^JANE^M — a fully populated synthetic name used consistently across this NK1 example.

Where this trips people up

Teams reuse their PID-5 name-parsing logic for NK1-2 and assume the same completeness guarantees, but next-of-kin names are frequently entered by front-desk staff under time pressure and show up with only a last name, or with a nickname jammed into the family-name component. Test data that always supplies a tidy full name never exposes the display and matching bugs that a bare "MOTHER" or single-word entry causes downstream.

→

HL7 v2 NK1 Segment Guide: Fields, Format, and Testing Gotchas

→

Synthetic Patient Data: Complete Guide for Software Testing

→

HL7 ADT Messages: A01 through A08 Explained

Stress-test name parsing with realistic partial data

Synthibase can generate NK1-2 values ranging from fully structured names to sparse, real-world-messy entries, so your parsing logic gets tested against what actually shows up in production.

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