diff --git a/helfi_tpr.install b/helfi_tpr.install
index 96318ab..7f35cd5 100644
--- a/helfi_tpr.install
+++ b/helfi_tpr.install
@@ -300,3 +300,22 @@ function helfi_tpr_update_8045() : void {
   \Drupal::entityDefinitionUpdateManager()
     ->installFieldStorageDefinition('topical', 'tpr_unit', 'helfi_tpr', $topical_field);
 }
+
+/**
+ * UHF-9159 Add SUBGROUP field to Unit entity.
+ */
+function helfi_tpr_update_8046() : void {
+  $subgroup_field = BaseFieldDefinition::create('tpr_connection')
+    ->setLabel(new TranslatableMarkup('Contact details of daycare centre groups', [], ['context' => 'TPR Unit field label']))
+    ->setDescription(new TranslatableMarkup('The "SUBGROUP" connection type'))
+    ->setTranslatable(TRUE)
+    ->setCardinality(BaseFieldDefinition::CARDINALITY_UNLIMITED)
+    ->setDisplayOptions('form', [
+      'type' => 'readonly_field_widget',
+    ])
+    ->setDisplayConfigurable('form', TRUE)
+    ->setDisplayConfigurable('view', TRUE);
+
+  \Drupal::entityDefinitionUpdateManager()
+    ->installFieldStorageDefinition('subgroup', 'tpr_unit', 'helfi_tpr', $subgroup_field);
+}
diff --git a/migrations/tpr_unit.yml b/migrations/tpr_unit.yml
index 89ea5e1..79a7fc0 100644
--- a/migrations/tpr_unit.yml
+++ b/migrations/tpr_unit.yml
@@ -104,6 +104,18 @@ process:
       value: value
       data: data
       type: type
+  _subgroup_connections:
+      plugin: array_element_equals
+      source: connections
+      value: SUBGROUP
+      key: type
+  subgroup:
+    plugin: sub_process
+    source: '@_subgroup_connections'
+    process:
+      value: value
+      data: data
+      type: type
   _contacts_connections:
       plugin: array_element_equals
       source: connections
diff --git a/src/Entity/Unit.php b/src/Entity/Unit.php
index 4489230..0652bdb 100644
--- a/src/Entity/Unit.php
+++ b/src/Entity/Unit.php
@@ -356,6 +356,10 @@ public static function baseFieldDefinitions(EntityTypeInterface $entity_type) :
         'description' => 'TOPICAL',
         'label' => new TranslatableMarkup('Topical', [], ['context' => 'TPR Unit field label']),
       ],
+      'subgroup' => [
+        'description' => 'SUBGROUP',
+        'label' => new TranslatableMarkup('Contact details of daycare centre groups', [], ['context' => 'TPR Unit field label']),
+      ],
     ];
 
     foreach ($connectionFields as $name => $data) {
diff --git a/src/Field/Connection/Repository.php b/src/Field/Connection/Repository.php
index dd238eb..2ad81f4 100644
--- a/src/Field/Connection/Repository.php
+++ b/src/Field/Connection/Repository.php
@@ -23,6 +23,7 @@ final class Repository {
     Link::TYPE_NAME => Link::class,
     PhoneOrEmail::TYPE_NAME => PhoneOrEmail::class,
     Topical::TYPE_NAME => Topical::class,
+    Subgroup::TYPE_NAME => Subgroup::class,
   ];
 
   /**
diff --git a/src/Field/Connection/Subgroup.php b/src/Field/Connection/Subgroup.php
new file mode 100644
index 0000000..1768244
--- /dev/null
+++ b/src/Field/Connection/Subgroup.php
@@ -0,0 +1,79 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\helfi_tpr\Field\Connection;
+
+use Drupal\Component\Render\FormattableMarkup;
+use Drupal\Component\Utility\Html;
+use Drupal\Core\Url;
+
+/**
+ * Provides a domain object for TPR connection type of Subgroup.
+ */
+final class Subgroup extends Connection {
+
+  /**
+   * The type name.
+   *
+   * @var string
+   */
+  public const TYPE_NAME = 'SUBGROUP';
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFields(): array {
+    return [
+      'name',
+      'contact_person',
+      'phone',
+      'email',
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build(): array {
+    $fields = $this->getFields();
+    $fields_data = [];
+
+    foreach ($fields as $field) {
+      if (!$this->get($field)) {
+        continue;
+      }
+
+      $data = Html::escape($this->get($field));
+
+      $fields_data[] = match ($field) {
+        'name' => [
+          '#markup' => '<strong>' . $data . '</strong>',
+        ],
+        'contact_person' => [
+          '#markup' => '<span>' . $data . '</span>',
+          '#prefix' => '<br />',
+        ],
+        'email' => [
+          '#url' => Url::fromUri('mailto:' . $data),
+          '#title' => new FormattableMarkup($data, []),
+          '#type' => 'link',
+          '#prefix' => '<br />',
+        ],
+        'phone' => [
+          '#url' => Url::fromUri('tel:' . $data),
+          '#title' => new FormattableMarkup($data, []),
+          '#type' => 'link',
+          '#prefix' => '<br />',
+        ],
+      };
+    }
+
+    $build = [
+      'subgroup' => $fields_data,
+    ];
+
+    return $build;
+  }
+
+}
diff --git a/src/Fixture/Unit.php b/src/Fixture/Unit.php
index 8af98f1..83616f2 100644
--- a/src/Fixture/Unit.php
+++ b/src/Fixture/Unit.php
@@ -690,6 +690,26 @@ public function getMockData() : array {
             'www_en' => 'https://localhost/en',
             'www_sv' => 'https://localhost/sv',
           ],
+          [
+            'unit_id' => 1,
+            'section_type' => 'SUBGROUP',
+            'name_fi' => 'subgroup fi 1',
+            'name_en' => 'subgroup en 1',
+            'name_sv' => 'subgroup sv 1',
+            'contact_person' => 'subgroup contact person name',
+            'phone' => '0406543210',
+            'email' => 'subgroup@example.com',
+          ],
+          [
+            'unit_id' => 1,
+            'section_type' => 'SUBGROUP',
+            'name_fi' => 'subgroup fi 2',
+            'name_en' => 'subgroup en 2',
+            'name_sv' => 'subgroup sv 2',
+            'contact_person' => 'subgroup contact person name 2',
+            'phone' => '0506543210',
+            'email' => 'subgroup2@example.com',
+          ],
         ],
         'provided_languages' => [
           'fi',
diff --git a/tests/src/Kernel/UnitMigrationTest.php b/tests/src/Kernel/UnitMigrationTest.php
index 115a91c..16a6416 100644
--- a/tests/src/Kernel/UnitMigrationTest.php
+++ b/tests/src/Kernel/UnitMigrationTest.php
@@ -12,6 +12,7 @@
 use Drupal\helfi_tpr\Field\Connection\OtherInfo;
 use Drupal\helfi_tpr\Field\Connection\PhoneOrEmail;
 use Drupal\helfi_tpr\Field\Connection\Price;
+use Drupal\helfi_tpr\Field\Connection\Subgroup;
 use Drupal\helfi_tpr\Field\Connection\Topical;
 
 /**
@@ -72,6 +73,7 @@ public function testUnitMigration() : void {
         $this->assertEquals("price $langcode $delta", $translation->get('price_info')->get($i)->value);
         $this->assertEquals("other info $langcode $delta", $translation->get('other_info')->get($i)->value);
         $this->assertEquals("topical $langcode $delta", $translation->get('topical')->get($i)->value);
+        $this->assertEquals("subgroup $langcode $delta", $translation->get('subgroup')->get($i)->value);
       }
 
       $opening_hour = $translation->get('opening_hours')->get(1)->data;
@@ -102,6 +104,12 @@ public function testUnitMigration() : void {
       $topical = $translation->get('topical')->get(0)->data;
       $this->assertInstanceOf(Topical::class, $topical);
       $this->assertEquals("https://localhost/$langcode", $links->get('www'));
+
+      $subgroup = $translation->get('subgroup')->get(0)->data;
+      $this->assertInstanceOf(Subgroup::class, $subgroup);
+      $this->assertEquals("subgroup contact person name", $subgroup->get('contact_person'));
+      $this->assertEquals("0406543210", $subgroup->get('phone'));
+      $this->assertEquals("subgroup@example.com", $subgroup->get('email'));
     }
 
     // Re-run migrate and make sure migrate map hash doesn't change.
diff --git a/tests/src/Unit/ConnectionRepositoryTest.php b/tests/src/Unit/ConnectionRepositoryTest.php
index 33633aa..ba60c6d 100644
--- a/tests/src/Unit/ConnectionRepositoryTest.php
+++ b/tests/src/Unit/ConnectionRepositoryTest.php
@@ -12,6 +12,7 @@
 use Drupal\helfi_tpr\Field\Connection\PhoneOrEmail;
 use Drupal\helfi_tpr\Field\Connection\Price;
 use Drupal\helfi_tpr\Field\Connection\Repository;
+use Drupal\helfi_tpr\Field\Connection\Subgroup;
 use Drupal\helfi_tpr\Field\Connection\Topical;
 use Drupal\Tests\UnitTestCase;
 
@@ -74,6 +75,7 @@ public function getTestData() : array {
       [Price::TYPE_NAME],
       [PhoneOrEmail::TYPE_NAME],
       [Topical::TYPE_NAME],
+      [Subgroup::TYPE_NAME],
     ];
   }
 
diff --git a/tests/src/Unit/ConnectionTest.php b/tests/src/Unit/ConnectionTest.php
index 51a37e1..bb01a7a 100644
--- a/tests/src/Unit/ConnectionTest.php
+++ b/tests/src/Unit/ConnectionTest.php
@@ -11,6 +11,7 @@
 use Drupal\helfi_tpr\Field\Connection\OtherInfo;
 use Drupal\helfi_tpr\Field\Connection\PhoneOrEmail;
 use Drupal\helfi_tpr\Field\Connection\Price;
+use Drupal\helfi_tpr\Field\Connection\Subgroup;
 use Drupal\helfi_tpr\Field\Connection\TextWithLink;
 use Drupal\helfi_tpr\Field\Connection\Topical;
 
@@ -198,6 +199,36 @@ public function testTopical() : void {
     $this->assertNotEmpty($object->build());
   }
 
+  /**
+   * Tests subgroups.
+   *
+   * @covers \Drupal\helfi_tpr\Field\Connection\Subgroup::build
+   * @covers \Drupal\helfi_tpr\Field\Connection\Subgroup::getFields
+   * @covers ::set
+   * @covers ::get
+   * @covers ::isValidField
+   */
+  public function testSubgroup() : void {
+    $object = new Subgroup();
+    $object->set('name', 'Some information.');
+    $this->assertNotEmpty($object->build());
+
+    // Make sure we can override data.
+    $object->set('name', 'override');
+    $this->assertNotEmpty($object->build());
+
+    $this->assertEquals(['name', 'contact_person', 'phone', 'email'], $object->getFields());
+
+    $this->assertNull($object->get('www'));
+
+    $object->set('contact_person', 'John Doe');
+    $this->assertNotEmpty($object->build());
+    $object->set('phone', '040123456');
+    $this->assertNotEmpty($object->build());
+    $object->set('email', 'john.doe@example.com');
+    $this->assertNotEmpty($object->build());
+  }
+
   /**
    * Tests invalid field name.
    *
diff --git a/translations/fi.po b/translations/fi.po
index 0364897..007c198 100644
--- a/translations/fi.po
+++ b/translations/fi.po
@@ -115,3 +115,7 @@ msgstr "Ajankohtaista"
 msgctxt "TPR Unit field label"
 msgid "Highlights"
 msgstr "Nostot"
+
+msgctxt "TPR Unit field label"
+msgid "Contact details of daycare centre groups"
+msgstr "Päiväkotiryhmien yhteystiedot"
diff --git a/translations/sv.po b/translations/sv.po
index fb9162f..7b1e270 100644
--- a/translations/sv.po
+++ b/translations/sv.po
@@ -100,3 +100,7 @@ msgstr "Aktuell"
 msgctxt "TPR Unit field label"
 msgid "Highlights"
 msgstr "Höjdpunkt"
+
+msgctxt "TPR Unit field label"
+msgid "Contact details of daycare centre groups"
+msgstr "Barngruppernas kontaktuppgifter"