diff --git a/core/lib/Drupal/Component/Serialization/TaggedSerializationInterface.php b/core/lib/Drupal/Component/Serialization/TaggedSerializationInterface.php
index 361ea65bf5..65903e5b33 100644
--- a/core/lib/Drupal/Component/Serialization/TaggedSerializationInterface.php
+++ b/core/lib/Drupal/Component/Serialization/TaggedSerializationInterface.php
@@ -7,6 +7,25 @@
  */
 interface TaggedSerializationInterface extends SerializationInterface {
 
+  /**
+   * Adds a tag callback.
+   *
+   * @param string $tag
+   *   The tag name.
+   * @param callable $callback
+   *   The callback to perform on a following value when the tag is encountered.
+   */
+  public static function addTagCallback($tag, callable $callback);
+
+  /**
+   * Provides the default tag callbacks of the serializer.
+   *
+   * @return array
+   *   An associative array where the key is the tag and the value is the
+   *   callback.
+   */
+  public static function getDefaultTagCallbacks();
+
   /**
    * Retrieves a map of tag callbacks.
    *
@@ -16,13 +35,24 @@ interface TaggedSerializationInterface extends SerializationInterface {
    */
   public static function getTagCallbacks();
 
+  /**
+   * Removes a tag callback.
+   *
+   * @param string $tag
+   *   The tag name.
+   *
+   * @return callable|null
+   *   The callback that was assigned to $tag or NULL if $tag didn't exist.
+   */
+  public static function removeTagCallback($tag);
+
   /**
    * Sets a map of tag callbacks.
    *
    * @param array $callbacks
-   *   An associative array where the key is the tag and the value is the
-   *   callback.
+   *   Optional. An associative array where the key is the tag and the value is
+   *   the callback. If not provided, the callbacks will be reset.
    */
-  public static function setTagCallbacks(array $callbacks);
+  public static function setTagCallbacks(array $callbacks = NULL);
 
 }
diff --git a/core/lib/Drupal/Component/Serialization/TaggedSerializationTrait.php b/core/lib/Drupal/Component/Serialization/TaggedSerializationTrait.php
index 8253479841..fb653b647e 100644
--- a/core/lib/Drupal/Component/Serialization/TaggedSerializationTrait.php
+++ b/core/lib/Drupal/Component/Serialization/TaggedSerializationTrait.php
@@ -12,7 +12,21 @@ trait TaggedSerializationTrait {
    *
    * @var array
    */
-  protected static $tagCallbacks = [];
+  protected static $tagCallbacks;
+
+  /**
+   * Adds a tag callback.
+   *
+   * @param string $tag
+   *   The tag name.
+   * @param callable $callback
+   *   The callback to perform on a following value when the tag is encountered.
+   */
+  public static function addTagCallback($tag, callable $callback) {
+    $callbacks = static::getTagCallbacks();
+    $callbacks[$tag] = $callback;
+    static::setTagCallbacks($callbacks);
+  }
 
   /**
    * Executes a tag callback.
@@ -28,12 +42,28 @@ trait TaggedSerializationTrait {
   public static function executeTagCallback($value, $tag) {
     $callbacks = static::getTagCallbacks();
 
+    // Prepend tag with ! (in cases where it's stripped from the name).
+    if ($tag[0] !== '!') {
+      $tag = "!$tag";
+    }
+
     // Immediately return the original value if there is no callback.
     if (!isset($callbacks[$tag])) {
       return $value;
     }
 
-    return $callbacks[$tag](...(array) $value);
+    return $callbacks[$tag]($value, $tag);
+  }
+
+  /**
+   * Provides the default tag callbacks.
+   *
+   * @return array
+   *   An associative array where the key is the tag and the value is the
+   *   callback.
+   */
+  public static function getDefaultTagCallbacks() {
+    return [];
   }
 
   /**
@@ -44,6 +74,9 @@ public static function executeTagCallback($value, $tag) {
    *   callback.
    */
   public static function getTagCallbacks() {
+    if (!isset(static::$tagCallbacks)) {
+      static::$tagCallbacks = static::getDefaultTagCallbacks();
+    }
     return static::$tagCallbacks;
   }
 
@@ -62,6 +95,24 @@ protected static function mergeTagCallbacks($serializer) {
     }
   }
 
+  /**
+   * Removes a tag callback.
+   *
+   * @param string $tag
+   *   The tag name.
+   *
+   * @return callable|null
+   *   The callback that was assigned to $tag or NULL if $tag didn't exist.
+   */
+  public static function removeTagCallback($tag) {
+    $callback = NULL;
+    if (isset(static::$tagCallbacks[$tag])) {
+      $callback = static::$tagCallbacks[$tag];
+      unset(static::$tagCallbacks[$tag]);
+    }
+    return $callback;
+  }
+
   /**
    * Sets a map of tag callbacks.
    *
@@ -69,7 +120,7 @@ protected static function mergeTagCallbacks($serializer) {
    *   An associative array where the key is the tag and the value is the
    *   callback.
    */
-  public static function setTagCallbacks(array $callbacks) {
+  public static function setTagCallbacks(array $callbacks = NULL) {
     static::$tagCallbacks = $callbacks;
   }
 
diff --git a/core/lib/Drupal/Component/Serialization/YamlPecl.php b/core/lib/Drupal/Component/Serialization/YamlPecl.php
index 651355b49b..260594db8b 100644
--- a/core/lib/Drupal/Component/Serialization/YamlPecl.php
+++ b/core/lib/Drupal/Component/Serialization/YamlPecl.php
@@ -57,6 +57,15 @@ public static function decode($raw) {
     return $data;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public static function getDefaultTagCallbacks() {
+    return [
+      YAML_BOOL_TAG => 'Drupal\Component\Serialization\YamlPecl::applyBooleanCallbacks',
+    ];
+  }
+
   /**
    * Handles errors for \Drupal\Component\Serialization\YamlPecl::decode().
    *
@@ -79,15 +88,6 @@ public static function getFileExtension() {
     return 'yml';
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public static function getTagCallbacks() {
-    return [
-      YAML_BOOL_TAG => static::class . '::applyBooleanCallbacks',
-    ];
-  }
-
   /**
    * Applies callbacks after parsing to ignore 1.1 style booleans.
    *
diff --git a/core/lib/Drupal/Component/Serialization/YamlSymfony.php b/core/lib/Drupal/Component/Serialization/YamlSymfony.php
index ae6fce4f8b..33a9aa7f57 100644
--- a/core/lib/Drupal/Component/Serialization/YamlSymfony.php
+++ b/core/lib/Drupal/Component/Serialization/YamlSymfony.php
@@ -47,7 +47,7 @@ public static function decode($raw) {
       // Support Symfony 3.3 TaggedValue objects.
       array_walk_recursive($data, function (&$item) {
         if ($item instanceof TaggedValue) {
-          $item = static::executeTagCallback($item->getValue(), '!' . $item->getTag());
+          $item = static::executeTagCallback($item->getValue(), $item->getTag());
         }
       });
 
diff --git a/core/lib/Drupal/Core/Serialization/Yaml.php b/core/lib/Drupal/Core/Serialization/Yaml.php
index 392b6fe86b..77440e7c83 100644
--- a/core/lib/Drupal/Core/Serialization/Yaml.php
+++ b/core/lib/Drupal/Core/Serialization/Yaml.php
@@ -2,7 +2,6 @@
 
 namespace Drupal\Core\Serialization;
 
-use Drupal\Component\Serialization\TaggedSerializationInterface;
 use Drupal\Core\Site\Settings;
 use Drupal\Component\Serialization\Yaml as ComponentYaml;
 
@@ -30,10 +29,8 @@ protected static function getSerializer() {
 
       static::$serializer = $class;
 
-      // Merge the tag callbacks from this proxy to the chosen serializer.
-      if (static::$serializer instanceof TaggedSerializationInterface) {
-        static::mergeTagCallbacks(static::$serializer);
-      }
+      // Merge any tag callbacks from this proxy to the chosen serializer.
+      static::mergeTagCallbacks(static::$serializer);
     }
     return parent::getSerializer();
   }
@@ -54,7 +51,7 @@ protected static function getTranslation() {
   /**
    * {@inheritdoc}
    */
-  public static function getTagCallbacks() {
+  public static function getDefaultTagCallbacks() {
     return [
       '!translate' => static::class . '::applyTranslateCallback',
     ];
@@ -63,14 +60,16 @@ public static function getTagCallbacks() {
   /**
    * Callback for applying the !translate tag.
    *
-   * @param mixed ...
-   *   The arguments to pass to the Translation manager.
+   * @param string|string[] $value
+   *   The tag value.
+   * @param string $tag
+   *   The tag name.
    *
    * @return \Drupal\Core\StringTranslation\TranslatableMarkup
    *   A new TranslatableMarkup object.
    */
-  public static function applyTranslateCallback(...$args) {
-    return static::getTranslation()->translate(...$args);
+  public static function applyTranslateCallback($value, $tag) {
+    return static::getTranslation()->translate(...(array) $value);
   }
 
 }
diff --git a/core/tests/Drupal/KernelTests/Core/Serialization/YamlTest.php b/core/tests/Drupal/KernelTests/Core/Serialization/YamlTest.php
new file mode 100644
index 0000000000..d2a62f2798
--- /dev/null
+++ b/core/tests/Drupal/KernelTests/Core/Serialization/YamlTest.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace Drupal\KernelTests\Core\Serialization;
+
+use Drupal\Core\Serialization\Yaml;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Tests service provider registration to the DIC.
+ *
+ * @covers \Drupal\Core\Serialization\Yaml
+ *
+ * @group Serialization
+ */
+class YamlTest extends KernelTestBase {
+
+  /**
+   * Test the YAML !translate tag functionality.
+   *
+   * @covers \Drupal\Core\Serialization\Yaml::applyTranslateCallback
+   */
+  public function testTranslateTag() {
+    $yaml = 'label: !translate [ "Label with @arg", { "@arg": "value" }, { context: "Something" } ]';
+    $data = Yaml::decode($yaml);
+
+    /* @var \Drupal\Core\StringTranslation\TranslatableMarkup $label */
+    $label = $data['label'];
+
+    // Ensure the label is a TranslatableMarkup instance.
+    $this->assertInstanceOf(TranslatableMarkup::class, $label);
+
+    // Ensure that the argument was set properly.
+    $this->assertEquals(['@arg' => 'value'], $label->getArguments());
+
+    // Ensure that the context option was set properly.
+    $this->assertEquals('Something', $label->getOption('context'));
+  }
+
+}
diff --git a/core/tests/Drupal/Tests/Component/Serialization/YamlPeclTest.php b/core/tests/Drupal/Tests/Component/Serialization/YamlPeclTest.php
index 910a6356b8..cdd978f077 100644
--- a/core/tests/Drupal/Tests/Component/Serialization/YamlPeclTest.php
+++ b/core/tests/Drupal/Tests/Component/Serialization/YamlPeclTest.php
@@ -96,4 +96,17 @@ public function testError() {
     YamlPecl::decode('foo: [ads');
   }
 
+  /**
+   * Tests YAML 1.2 tag support (!tag).
+   *
+   * @covers ::addTagCallback
+   * @covers ::getDefaultTagCallbacks
+   * @covers ::getTagCallbacks
+   * @covers ::removeTagCallback
+   * @covers ::setTagCallbacks
+   */
+  public function testTagSupport() {
+    $this->assertYamlTags(YamlPecl::class);
+  }
+
 }
diff --git a/core/tests/Drupal/Tests/Component/Serialization/YamlSymfonyTest.php b/core/tests/Drupal/Tests/Component/Serialization/YamlSymfonyTest.php
index eeedf538d6..9b99d84599 100644
--- a/core/tests/Drupal/Tests/Component/Serialization/YamlSymfonyTest.php
+++ b/core/tests/Drupal/Tests/Component/Serialization/YamlSymfonyTest.php
@@ -87,4 +87,17 @@ public function testObjectSupportDisabled() {
     YamlSymfony::encode([$object]);
   }
 
+  /**
+   * Tests YAML 1.2 tag support (!tag).
+   *
+   * @covers ::addTagCallback
+   * @covers ::getDefaultTagCallbacks
+   * @covers ::getTagCallbacks
+   * @covers ::removeTagCallback
+   * @covers ::setTagCallbacks
+   */
+  public function testTagSupport() {
+    $this->assertYamlTags(YamlSymfony::class);
+  }
+
 }
diff --git a/core/tests/Drupal/Tests/Component/Serialization/YamlTestBase.php b/core/tests/Drupal/Tests/Component/Serialization/YamlTestBase.php
index 82226d0d34..1c9e25848e 100644
--- a/core/tests/Drupal/Tests/Component/Serialization/YamlTestBase.php
+++ b/core/tests/Drupal/Tests/Component/Serialization/YamlTestBase.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\Component\Serialization;
 
+use Drupal\Component\Serialization\TaggedSerializationInterface;
 use PHPUnit\Framework\TestCase;
 
 /**
@@ -9,6 +10,55 @@
  */
 abstract class YamlTestBase extends TestCase {
 
+  /**
+   * Asserts that a serializer can support YAML 1.2 tags.
+   *
+   * @param string $serializer
+   *   The class name of the serializer to test.
+   */
+  protected function assertYamlTags($serializer) {
+    /* @var \Drupal\Component\Serialization\TaggedSerializationInterface $serializer */
+
+    // Ensure the serializer supports the tagged interface.
+    $this->assertTrue(is_subclass_of($serializer, TaggedSerializationInterface::class));
+
+    // Ensure the component's default callbacks.
+    $this->assertEquals($serializer::getDefaultTagCallbacks(), $serializer::getTagCallbacks());
+
+    $yaml = 'value: !sum [1, 2, 3]';
+
+    // Ensure that without a callback, the tag is ignored.
+    $data = $serializer::decode($yaml);
+    $this->assertEquals($data['value'], [1, 2, 3]);
+
+    // Now, add the custom tag callback.
+    $sum = function ($value, $tag) {
+      return array_sum($value);
+    };
+    $serializer::addTagCallback('!sum', $sum);
+
+    // Ensure that with a tag callback, the value is converted.
+    $data = $serializer::decode($yaml);
+    $this->assertEquals($data['value'], 6);
+
+    // Remove the custom tag callback and ensure it returns original callback.
+    $callback = $serializer::removeTagCallback('!sum');
+    $this->assertEquals($sum, $callback);
+
+    // Ensure that without a callback, the tag is ignored.
+    $data = $serializer::decode($yaml);
+    $this->assertEquals($data['value'], [1, 2, 3]);
+
+    // Reset tag callbacks.
+    $serializer::setTagCallbacks();
+    $callbacks = new \ReflectionProperty($serializer, 'tagCallbacks');
+    $callbacks->setAccessible(TRUE);
+    $this->assertEquals(NULL, $callbacks->getValue($serializer));
+
+    // Ensure the component's default callbacks are restored.
+    $this->assertEquals($serializer::getDefaultTagCallbacks(), $serializer::getTagCallbacks());
+  }
+
   /**
    * Some data that should be able to be serialized.
    */