diff -u b/core/modules/filter/migration_templates/d6_filter_format.yml b/core/modules/filter/migration_templates/d6_filter_format.yml
--- b/core/modules/filter/migration_templates/d6_filter_format.yml
+++ b/core/modules/filter/migration_templates/d6_filter_format.yml
@@ -15,8 +15,10 @@
     source: filters
     key: '@id'
     process:
-      id:
-        plugin: static_map
+      id:g
+        # Because the bypass flag is not set, the row will be skipped
+        # entirely if the filter ID cannot be determined.
+        plugin: filter_id
         source:
           - module
           - delta
@@ -27,8 +29,6 @@
             - filter_url
             - filter_htmlcorrector
             - filter_html_escape
-          php:
-            - filter_null
       settings:
         plugin: filter_settings
         source: settings
diff -u b/core/modules/filter/migration_templates/d7_filter_format.yml b/core/modules/filter/migration_templates/d7_filter_format.yml
--- b/core/modules/filter/migration_templates/d7_filter_format.yml
+++ b/core/modules/filter/migration_templates/d7_filter_format.yml
@@ -15,13 +15,16 @@
     key: '@id'
     process:
       id:
-        plugin: static_map
+        # If the filter ID cannot be mapped, it will pass through unmodified
+        # because the bypass flag is set. When the user actually tries to
+        # view text through an invalid filter plugin, the filter system will
+        # fall back to filter_null and display a helpful error message.
+        plugin: filter_id
         bypass: true
         source: name
-        map:
-          # Change the php_code filter to filter_null; other filters can pass
-          # through unmodified.
-          php_code: filter_null
+        # No need to map anything -- filter plugin IDs haven't changed since
+        # Drupal 7.
+        map: { }
       settings:
         plugin: filter_settings
         source: settings
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/filter/src/Plugin/migrate/process/FilterID.php
@@ -0,0 +1,78 @@
+<?php
+
+namespace Drupal\filter\Plugin\migrate\process;
+
+use Drupal\Component\Plugin\Exception\PluginNotFoundException;
+use Drupal\Component\Plugin\PluginManagerInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\migrate\MigrateExecutableInterface;
+use Drupal\migrate\Plugin\migrate\process\StaticMap;
+use Drupal\migrate\Row;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * @MigrateProcessPlugin(
+ *   id = "filter_id"
+ * )
+ */
+class FilterID extends StaticMap implements ContainerFactoryPluginInterface {
+
+  /**
+   * The filter plugin manager.
+   *
+   * @var \Drupal\Component\Plugin\PluginManagerInterface
+   */
+  protected $filterManager;
+
+  /**
+   * FilterID constructor.
+   *
+   * @param array $configuration
+   *   Plugin configuration.
+   * @param string $plugin_id
+   *   The plugin ID.
+   * @param mixed $plugin_definition
+   *   The plugin definition.
+   * @param \Drupal\Component\Plugin\PluginManagerInterface $filter_manager
+   *   The filter plugin manager.
+   */
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, PluginManagerInterface $filter_manager) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+    $this->filterManager = $filter_manager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('plugin.manager.filter')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
+    $plugin_id = parent::transform($value, $migrate_executable, $row, $destination_property);
+
+    // Try to create an instance of the filter to ensure that it actually
+    // exists. If it doesn't, the filter manager will throw an exception,
+    // which we'll catch and log so as to inform the user that they've tried
+    // to migrate an invalid filter. But we'll let the invalid value pass
+    // through anyway -- the filter system will fall back to filter_null and
+    // the user can deal with it later.
+    try {
+      $this->filterManager->createInstance($plugin_id);
+    }
+    catch (PluginNotFoundException $e) {
+      $migrate_executable->saveMessage($e->getMessage());
+    }
+
+    return $plugin_id;
+  }
+
+}