diff --git a/sendgrid/helpers/mail/asm.py b/sendgrid/helpers/mail/asm.py
index b4889ead2..59e49eee5 100644
--- a/sendgrid/helpers/mail/asm.py
+++ b/sendgrid/helpers/mail/asm.py
@@ -41,6 +41,8 @@ def groups_to_display(self):
 
     @groups_to_display.setter
     def groups_to_display(self, value):
+        if value is not None and len(value) > 25:
+            raise ValueError("New groups_to_display exceeds max length of 25.")
         self._groups_to_display = value
 
     def get(self):
diff --git a/test/test_mail.py b/test/test_mail.py
index 3356eef52..8b88f5b14 100644
--- a/test/test_mail.py
+++ b/test/test_mail.py
@@ -468,6 +468,9 @@ def test_unicode_values_in_substitutions_helper(self):
             json.dumps(expected_result, sort_keys=True)
         )
 
+    def test_asm_display_group_limit(self):
+        self.assertRaises(ValueError, ASM, 1, list(range(26)))
+
     def test_disable_tracking(self):
         tracking_settings = TrackingSettings()
         tracking_settings.click_tracking = ClickTracking(False, False)