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Healthcare/HL7 v2/NK1
Segment

Next of kin / associated parties

Identifies the patient's next of kin, emergency contacts, and other associated parties such as guardians or power of attorney, including their names, relationship, addresses, and phone numbers. It repeats to carry multiple contacts and is included in ADT messages, referrals, and BAR transactions. Registration and EHR systems send NK1 data for use by emergency departments, social services, and billing systems.

38fields
1required
v2.9HL7 version
nk1.py
from zato.hl7v2 import NK1

nk1 = NK1()
nk1.set_id_nk1 = '1'
nk1.name = 'SMITH^JANE'
nk1.relationship = 'SPO'
nk1.phone_number = '5551234567'
Python examples

Build NK1 segments in Python

How to construct and work with real-world NK1 segments.

1

Emergency contact — spouse with address

Records a spouse as the primary emergency contact with their name, relationship, and home address for coordination purposes

from zato.hl7v2.v2_9 import NK1
from zato.hl7v2.v2_9 import CWE, XAD, XPN

nk1 = NK1()
nk1.set_id_nk1 = '1'
nk1.name = XPN(
    family_name='SMITH',
    given_name='JANE'
)
nk1.relationship = CWE(
    identifier='SPO',
    text='Spouse',
    name_of_coding_system='HL70063'
)
nk1.address = XAD(
    street_address='742 Evergreen Terrace',
    city='Springfield',
    state_or_province='IL',
    zip_or_postal_code='62704'
)
2

Parent as next of kin with contact role and organization

Records a parent contact with an emergency contact role and an associated organization for benefits coordination

from zato.hl7v2.v2_9 import NK1
from zato.hl7v2.v2_9 import CWE, XAD, XON, XPN

nk1 = NK1()
nk1.set_id_nk1 = '2'
nk1.name = XPN(
    family_name='JOHNSON',
    given_name='ROBERT'
)
nk1.relationship = CWE(
    identifier='PAR',
    text='Parent',
    name_of_coding_system='HL70063'
)
nk1.address = XAD(
    street_address='100 Oak Avenue',
    city='Portland',
    state_or_province='OR',
    zip_or_postal_code='97201'
)
nk1.contact_role = CWE(
    identifier='EC',
    text='Emergency Contact',
    name_of_coding_system='HL70131'
)
nk1.organization_name_nk1 = XON(organization_name='Greenvalley Wellness')
3

Sibling contact with job title and start date

Records a sibling as next of kin with a contact role, job title, and the date the contact relationship became effective

from zato.hl7v2.v2_9 import NK1
from zato.hl7v2.v2_9 import CWE, XPN

nk1 = NK1()
nk1.set_id_nk1 = '3'
nk1.name = XPN(
    family_name='WILLIAMS',
    given_name='SARAH'
)
nk1.relationship = CWE(
    identifier='SIB',
    text='Sibling',
    name_of_coding_system='HL70063'
)
nk1.contact_role = CWE(
    identifier='NK',
    text='Next of Kin',
    name_of_coding_system='HL70131'
)
nk1.start_date = '20240301'
nk1.next_of_kin_associated_parties_job_title = 'Wellness Coordinator'
Tutorials

Learn by building

Step-by-step guides for working with HL7 v2 in Zato.

MLLP
Receive and parse HL7 v2 messages
Set up an MLLP channel, parse incoming messages, and respond with acknowledgments.
Start tutorial Build
Build and send HL7 v2 messages
Construct HL7 v2 messages from scratch using typed segment classes and send them over MLLP.
Start tutorial
Related segments

Commonly used with NK1

PID Patient identification PD1 Patient additional demographic PV1 Patient visit IN1 Insurance GT1 Guarantor MSH Message header
FAQ

Frequently asked questions

NK1 carries information about a patient's next of kin, emergency contacts, guardians, and other associated parties. It includes their names, addresses, phone numbers, relationships, contact roles, and demographic details. It appears in ADT, registration, and scheduling messages.

Create an NK1 segment and read its fields directly:

from zato.hl7v2.v2_9 import NK1, XPN, CWE, XTN

nk1 = NK1()
nk1.name = XPN(family_name='SMITH',
    given_name='JANE')
nk1.relationship = CWE(identifier='SPO')
nk1.phone_number = XTN(
    telecommunication_use_code='PRN',
    local_number='5551234'
)

kin_name = nk1.name
relation = nk1.relationship
phone = nk1.phone_number

The relationship field uses the CWE datatype with HL7 table 0063 codes:

from zato.hl7v2.v2_9 import NK1, CWE

nk1 = NK1()
nk1.relationship = CWE(identifier='SPO')

# Common codes:
# SPO = Spouse
# PAR = Parent
# CHD = Child
# FRD = Friend
# GRD = Guardian

Create separate NK1 instances, each with its own set_id_nk1:

from zato.hl7v2.v2_9 import NK1, XPN, CWE

nk1_spouse = NK1()
nk1_spouse.set_id_nk1 = '1'
nk1_spouse.name = XPN(
    family_name='SMITH', given_name='JANE')
nk1_spouse.relationship = CWE(
    identifier='SPO')

nk1_friend = NK1()
nk1_friend.set_id_nk1 = '2'
nk1_friend.name = XPN(
    family_name='JONES', given_name='BOB')
nk1_friend.relationship = CWE(
    identifier='FRD')

The organization_name_nk1 field uses the XON (extended composite organization name) datatype:

from zato.hl7v2.v2_9 import NK1, XON

nk1 = NK1()
nk1.organization_name_nk1 = XON(
    organization_name='Greenvalley Wellness',
    id_number='ORG-100'
)

Zato connects to any system that speaks HL7v2 over MLLP or FHIR over REST. This includes Epic, Cerner, Meditech, Allscripts, and other EHR platforms.

Yes, Zato has built-in MLLP support for sending and receiving HL7v2 messages. MLLP channels handle the framing protocol automatically.

Zato supports HL7 v2.9, which is backward compatible with earlier versions including v2.3, v2.5, and v2.7. Standard segments and datatypes are available as typed Python classes.

Yes. Zato handles both HL7v2 and FHIR natively, so you can parse v2 messages and build FHIR resources with IG-specific extensions in the same service. Typed Python classes are available for both protocols, including extensions from US Core, UK Core, Da Vinci, and other Implementation Guides.

Reference

NK1 field reference

Complete list of fields in the NK1 segment, HL7 v2.9.

#Python nameDatatypeUsageRepeatableTable
1set_id_nk1SIRequiredNo-
2▶nameXPNOptionalYesHL70200
3▶relationshipCWEOptionalNoHL70063
4▶addressXADOptionalYes-
7▶contact_roleCWEOptionalNoHL70131
8start_dateDTOptionalNo-
9end_dateDTOptionalNo-
10next_of_kin_associated_parties_job_titleSTOptionalNo-
11▶next_of_kin_associated_parties_job_code_classJCCOptionalNo-
12▶next_of_kin_associated_parties_employee_numberCXOptionalNo-
13▶organization_name_nk1XONOptionalYes-
14▶marital_statusCWEOptionalNoHL70002
15▶administrative_sexCWEOptionalNoHL70001
16date_time_of_birthDTMOptionalNo-
17▶living_dependencyCWEOptionalYesHL70223
18▶ambulatory_statusCWEOptionalYesHL70009
19▶citizenshipCWEOptionalYesHL70171
20▶primary_languageCWEOptionalNoHL70296
21▶living_arrangementCWEOptionalNoHL70220
22▶publicity_codeCWEOptionalNoHL70215
23protection_indicatorIDOptionalNoHL70136
24▶student_indicatorCWEOptionalNoHL70231
25▶religionCWEOptionalNoHL70006
26▶mothers_maiden_nameXPNOptionalYes-
27▶nationalityCWEOptionalNoHL70212
28▶ethnic_groupCWEOptionalYesHL70189
29▶contact_reasonCWEOptionalYesHL70222
30▶contact_persons_nameXPNOptionalYes-
32▶contact_persons_addressXADOptionalYes-
33▶next_of_kin_associated_partys_identifiersCXOptionalYes-
34▶job_statusCWEOptionalNoHL70311
35▶raceCWEOptionalYesHL70005
36▶handicapCWEOptionalNoHL70295
37contact_person_social_security_numberSTOptionalNo-
38next_of_kin_birth_placeSTOptionalNo-
39▶vip_indicatorCWEOptionalNoHL70099
40▶next_of_kin_telecommunication_informationXTNOptionalNo-
41▶contact_persons_telecommunication_informationXTNOptionalNo-

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