diff --git a/lib/smart_todo_assignment_rules_cop.rb b/lib/smart_todo_assignment_rules_cop.rb
new file mode 100644
index 0000000..3cc1de6
--- /dev/null
+++ b/lib/smart_todo_assignment_rules_cop.rb
@@ -0,0 +1,94 @@
+# frozen_string_literal: true
+
+require "smart_todo"
+
+module RuboCop
+  module Cop
+    module SmartTodo
+      # A RuboCop cop to enforce assignment rules for smart TODOs.
+      # This cop ensures that all smart TODOs (those with events and assignees) include
+      # all configured required assignees in their assignees list, helping teams enforce
+      # TODO assignment policies.
+      #
+      # Configuration:
+      #   SmartTodo/AssignmentRules:
+      #     RequiredAssignees:
+      #       - '#project-alerts'
+      #       - '@team-lead'
+      #
+      # @example
+      #   # bad - smart TODO without all required assignees
+      #   # TODO(on: date('2024-03-29'), to: 'john@example.com')
+      #   #   Do something
+      #
+      #   # good - smart TODO includes all required assignees
+      #   # TODO(on: date('2024-03-29'), to: 'john@example.com', to: '#project-alerts', to: '@team-lead')
+      #   #   Do something
+      #
+      # @see https://rubocop.readthedocs.io/en/latest/extensions/#loading-extensions
+      class AssignmentRules < Base
+        INVESTIGATED_TAGS = ::SmartTodo::CommentParser::SUPPORTED_TAGS +
+          ::SmartTodo::CommentParser::SUPPORTED_TAGS.map(&:downcase)
+        TODO_PATTERN = /^#\s@?(#{INVESTIGATED_TAGS.join("|")})\(/
+
+        # @param processed_source [RuboCop::ProcessedSource]
+        # @return [void]
+        def on_new_investigation
+          processed_source.comments.each do |comment|
+            next unless TODO_PATTERN.match?(comment.text)
+            next unless smart_todo?(comment)
+
+            missing_assignees = find_missing_assignees(comment)
+            next if missing_assignees.empty?
+
+            add_offense(comment, message: offense_message(missing_assignees))
+          end
+        end
+
+        private
+
+        # @return [Array<String>] The required assignees from configuration
+        # @raise [RuntimeError] if RequiredAssignees is not configured or empty
+        def required_assignees
+          @required_assignees ||= begin
+            assignees = cop_config["RequiredAssignees"]
+            if assignees.nil? || assignees.empty?
+              raise "RequiredAssignees must be set for SmartTodo/AssignmentRules"
+            end
+
+            assignees
+          end
+        end
+
+        # @param comment [RuboCop::AST::Comment]
+        # @return [true, false] Whether the comment is a smart TODO
+        def smart_todo?(comment)
+          metadata = ::SmartTodo::Todo.new(comment.text, line_number: comment.loc.line)
+
+          metadata.events.any? &&
+            metadata.events.all? { |event| event.is_a?(::SmartTodo::Todo::CallNode) } &&
+            metadata.assignees.any?
+        end
+
+        # @param comment [RuboCop::AST::Comment]
+        # @return [Array<String>] List of required assignees that are missing from the TODO
+        def find_missing_assignees(comment)
+          metadata = ::SmartTodo::Todo.new(comment.text, line_number: comment.loc.line)
+          todo_assignees = metadata.assignees.to_a
+
+          required_assignees.reject { |assignee| todo_assignees.include?(assignee) }
+        end
+
+        # @param missing_assignees [Array<String>]
+        # @return [String] The offense message
+        def offense_message(missing_assignees)
+          if missing_assignees.size == 1
+            "Smart TODO must include required assignee: #{missing_assignees.first}"
+          else
+            "Smart TODO must include required assignees: #{missing_assignees.join(", ")}"
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/test/smart_todo/smart_todo_assignment_rules_cop_test.rb b/test/smart_todo/smart_todo_assignment_rules_cop_test.rb
new file mode 100644
index 0000000..ab1c055
--- /dev/null
+++ b/test/smart_todo/smart_todo_assignment_rules_cop_test.rb
@@ -0,0 +1,329 @@
+# frozen_string_literal: true
+
+require "test_helper"
+require "rubocop"
+require "rubocop/rspec/expect_offense"
+require "smart_todo_assignment_rules_cop"
+
+module SmartTodo
+  class AssignmentRulesTest < Minitest::Test
+    def test_add_offense_when_smart_todo_missing_all_required_assignees
+      expect_offense(<<~RUBY)
+        # TODO(on: date('2024-03-29'), to: 'john@example.com')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_multiple}
+        #   Do something
+        def hello
+        end
+      RUBY
+    end
+
+    def test_add_offense_when_smart_todo_missing_one_required_assignee
+      expect_offense(<<~RUBY)
+        # TODO(on: date('2024-03-29'), to: 'john@example.com', to: '#project-alerts')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_single("@team-lead")}
+        #   Do something
+        def hello
+        end
+      RUBY
+    end
+
+    def test_add_offense_when_smart_todo_has_different_assignees
+      expect_offense(<<~RUBY)
+        # TODO(on: date('2024-03-29'), to: 'john@example.com', to: '#other-channel')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_multiple}
+        #   Do something
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_when_smart_todo_has_all_required_assignees
+      expect_no_offense(<<~RUBY)
+        # TODO(on: date('2024-03-29'), to: 'john@example.com', to: '#project-alerts', to: '@team-lead')
+        #   Do something
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_when_smart_todo_has_required_assignees_first
+      expect_no_offense(<<~RUBY)
+        # TODO(on: date('2024-03-29'), to: '#project-alerts', to: '@team-lead', to: 'john@example.com')
+        #   Do something
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_when_smart_todo_has_required_assignees_only
+      expect_no_offense(<<~RUBY)
+        # TODO(on: date('2024-03-29'), to: '#project-alerts', to: '@team-lead')
+        #   Do something
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_when_smart_todo_has_required_assignees_among_multiple
+      expect_no_offense(<<~RUBY)
+        # TODO(on: date('2024-03-29'), to: 'john@example.com', to: '#project-alerts', to: '@team-lead', to: 'jane@example.com')
+        #   Do something
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_when_comment_is_not_a_todo
+      expect_no_offense(<<~RUBY)
+        # This is a regular comment
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_when_todo_is_not_smart
+      expect_no_offense(<<~RUBY)
+        # TODO: Do this later
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_when_todo_has_event_but_no_assignee
+      expect_no_offense(<<~RUBY)
+        # TODO(on: date('2024-03-29'))
+        def hello
+        end
+      RUBY
+    end
+
+    def test_add_offense_when_fixme_missing_required_assignees
+      expect_offense(<<~RUBY)
+        # FIXME(on: date('2024-03-29'), to: 'john@example.com')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_multiple}
+        #   Fix something
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_when_fixme_has_required_assignees
+      expect_no_offense(<<~RUBY)
+        # FIXME(on: date('2024-03-29'), to: 'john@example.com', to: '#project-alerts', to: '@team-lead')
+        #   Fix something
+        def hello
+        end
+      RUBY
+    end
+
+    def test_add_offense_when_optimize_missing_required_assignees
+      expect_offense(<<~RUBY)
+        # OPTIMIZE(on: date('2024-03-29'), to: 'john@example.com')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_multiple}
+        #   Optimize something
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_when_optimize_has_required_assignees
+      expect_no_offense(<<~RUBY)
+        # OPTIMIZE(on: date('2024-03-29'), to: 'john@example.com', to: '#project-alerts', to: '@team-lead')
+        #   Optimize something
+        def hello
+        end
+      RUBY
+    end
+
+    def test_add_offense_with_issue_close_event
+      expect_offense(<<~RUBY)
+        # TODO(on: issue_close('shopify', 'smart_todo', '123'), to: 'john@example.com')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_multiple}
+        #   Do something when issue closes
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_with_issue_close_event_and_all_assignees
+      expect_no_offense(<<~RUBY)
+        # TODO(on: issue_close('shopify', 'smart_todo', '123'), to: 'john@example.com', to: '#project-alerts', to: '@team-lead')
+        #   Do something when issue closes
+        def hello
+        end
+      RUBY
+    end
+
+    def test_add_offense_with_pull_request_close_event
+      expect_offense(<<~RUBY)
+        # TODO(on: pull_request_close('shopify', 'smart_todo', '456'), to: 'john@example.com')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_multiple}
+        #   Do something when PR closes
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_with_pull_request_close_event_and_all_assignees
+      expect_no_offense(<<~RUBY)
+        # TODO(on: pull_request_close('shopify', 'smart_todo', '456'), to: 'john@example.com', to: '#project-alerts', to: '@team-lead')
+        #   Do something when PR closes
+        def hello
+        end
+      RUBY
+    end
+
+    def test_add_offense_with_gem_release_event
+      expect_offense(<<~RUBY)
+        # TODO(on: gem_release('rails', '>= 7.0'), to: 'john@example.com')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_multiple}
+        #   Do something when gem is released
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_with_gem_release_event_and_all_assignees
+      expect_no_offense(<<~RUBY)
+        # TODO(on: gem_release('rails', '>= 7.0'), to: 'john@example.com', to: '#project-alerts', to: '@team-lead')
+        #   Do something when gem is released
+        def hello
+        end
+      RUBY
+    end
+
+    def test_add_offense_with_gem_bump_event
+      expect_offense(<<~RUBY)
+        # TODO(on: gem_bump('rails', '>= 8.0'), to: 'john@example.com')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_multiple}
+        #   Do something when gem is bumped
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_with_gem_bump_event_and_all_assignees
+      expect_no_offense(<<~RUBY)
+        # TODO(on: gem_bump('rails', '>= 8.0'), to: 'john@example.com', to: '#project-alerts', to: '@team-lead')
+        #   Do something when gem is bumped
+        def hello
+        end
+      RUBY
+    end
+
+    def test_add_offense_with_ruby_version_event
+      expect_offense(<<~RUBY)
+        # TODO(on: ruby_version('>= 3.0'), to: 'john@example.com')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_multiple}
+        #   Do something when ruby version changes
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_with_ruby_version_event_and_all_assignees
+      expect_no_offense(<<~RUBY)
+        # TODO(on: ruby_version('>= 3.0'), to: 'john@example.com', to: '#project-alerts', to: '@team-lead')
+        #   Do something when ruby version changes
+        def hello
+        end
+      RUBY
+    end
+
+    def test_add_offense_with_lowercase_todo
+      expect_offense(<<~RUBY)
+        # todo(on: date('2024-03-29'), to: 'john@example.com')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_multiple}
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_with_lowercase_todo_and_all_assignees
+      expect_no_offense(<<~RUBY)
+        # todo(on: date('2024-03-29'), to: 'john@example.com', to: '#project-alerts', to: '@team-lead')
+        def hello
+        end
+      RUBY
+    end
+
+    def test_add_offense_with_multiple_smart_todos
+      expect_offense(<<~RUBY)
+        # TODO(on: date('2024-03-29'), to: 'john@example.com')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_multiple}
+        #   Do something
+
+        # FIXME(on: date('2024-04-15'), to: 'jane@example.com')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_multiple}
+        #   Fix something
+        def hello
+        end
+      RUBY
+    end
+
+    def test_add_offense_with_context_but_missing_assignees
+      expect_offense(<<~RUBY)
+        # TODO(on: date('2024-03-29'), to: 'john@example.com', context: "shopify/smart_todo#123")
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{expected_message_multiple}
+        #   Do something
+        def hello
+        end
+      RUBY
+    end
+
+    def test_does_not_add_offense_with_context_and_all_assignees
+      expect_no_offense(<<~RUBY)
+        # TODO(on: date('2024-03-29'), to: 'john@example.com', to: '#project-alerts', to: '@team-lead', context: "shopify/smart_todo#123")
+        #   Do something
+        def hello
+        end
+      RUBY
+    end
+
+    private
+
+    def expected_message_single(assignee)
+      "Smart TODO must include required assignee: #{assignee}"
+    end
+
+    def expected_message_multiple
+      "Smart TODO must include required assignees: #project-alerts, @team-lead"
+    end
+
+    def expect_offense(source)
+      annotated_source = RuboCop::RSpec::ExpectOffense::AnnotatedSource.parse(source)
+      report = investigate(annotated_source.plain_source)
+
+      actual_annotations = annotated_source.with_offense_annotations(report.offenses)
+      assert_equal(annotated_source.to_s, actual_annotations.to_s)
+    end
+
+    def expect_no_offense(source)
+      annotated_source = RuboCop::RSpec::ExpectOffense::AnnotatedSource.parse(source)
+      report = investigate(annotated_source.plain_source)
+
+      assert_empty(report.offenses, "Expected no offenses but got: #{report.offenses.map(&:message).join(", ")}")
+    end
+
+    def investigate(source, file = "(file)")
+      processed_source = RuboCop::ProcessedSource.new(source, RUBY_VERSION.to_f, file)
+
+      assert(processed_source.valid_syntax?)
+      comm = RuboCop::Cop::Commissioner.new([cop], [], raise_error: true)
+      comm.investigate(processed_source)
+    end
+
+    def cop
+      # Create a new cop instance with the required configuration
+      config = RuboCop::Config.new(
+        {
+          "SmartTodo/AssignmentRules" => {
+            "RequiredAssignees" => ["#project-alerts", "@team-lead"],
+          },
+        },
+        "(config)",
+      )
+      RuboCop::Cop::SmartTodo::AssignmentRules.new(config)
+    end
+  end
+end