diff --git a/cms/djangoapps/contentstore/rest_api/v1/serializers/course_waffle_flags.py b/cms/djangoapps/contentstore/rest_api/v1/serializers/course_waffle_flags.py
index 3a885f8c96bc..6db34b4cf34f 100644
--- a/cms/djangoapps/contentstore/rest_api/v1/serializers/course_waffle_flags.py
+++ b/cms/djangoapps/contentstore/rest_api/v1/serializers/course_waffle_flags.py
@@ -156,7 +156,7 @@ def get_enable_course_optimizer(self, obj):
 
     def get_use_react_markdown_editor(self, obj):
         """
-        Method to get the use_react_markdown_editor waffle flag
+        Determine whether the new markdown editor should be enabled in the react problem editor
         """
         course_key = self.get_course_key()
         return toggles.use_react_markdown_editor(course_key)
diff --git a/cms/djangoapps/contentstore/rest_api/v1/views/tests/test_course_waffle_flags.py b/cms/djangoapps/contentstore/rest_api/v1/views/tests/test_course_waffle_flags.py
index 1d58f99d386c..61435c19c948 100644
--- a/cms/djangoapps/contentstore/rest_api/v1/views/tests/test_course_waffle_flags.py
+++ b/cms/djangoapps/contentstore/rest_api/v1/views/tests/test_course_waffle_flags.py
@@ -33,7 +33,7 @@ class CourseWaffleFlagsViewTest(CourseTestCase):
         'use_new_unit_page': True,
         'use_new_updates_page': True,
         'use_new_video_uploads_page': False,
-        'use_react_markdown_editor': False,
+        'use_react_markdown_editor': True,
     }
 
     def setUp(self):
diff --git a/cms/djangoapps/contentstore/toggles.py b/cms/djangoapps/contentstore/toggles.py
index 232bfc45d242..cea753fe7963 100644
--- a/cms/djangoapps/contentstore/toggles.py
+++ b/cms/djangoapps/contentstore/toggles.py
@@ -219,22 +219,22 @@ def use_new_custom_pages(course_key):
     return not LEGACY_STUDIO_CUSTOM_PAGES.is_enabled(course_key)
 
 
-# .. toggle_name: contentstore.use_react_markdown_editor
+# .. toggle_name: contentstore.disable_react_markdown_editor
 # .. toggle_implementation: CourseWaffleFlag
 # .. toggle_default: False
-# .. toggle_description: This flag enables the use of the Markdown editor when creating or editing problems in the authoring MFE
-# .. toggle_use_cases: opt_in
+# .. toggle_description: This flag disables the use of the Markdown editor when creating or editing problems in the authoring MFE
+# .. toggle_use_cases: opt_out
 # .. toggle_creation_date: 2025-4-11
 # .. toggle_tickets: https://openedx.atlassian.net/wiki/spaces/OEPM/pages/4517232656/Re-enable+Markdown+editing+of+CAPA+problems+to+meet+various+use+cases
-ENABLE_REACT_MARKDOWN_EDITOR = CourseWaffleFlag(
-    f'{CONTENTSTORE_NAMESPACE}.use_react_markdown_editor', __name__)
+DISABLE_REACT_MARKDOWN_EDITOR = CourseWaffleFlag(
+    f'{CONTENTSTORE_NAMESPACE}.disable_react_markdown_editor', __name__)
 
 
 def use_react_markdown_editor(course_key):
     """
     Returns a boolean if new studio custom pages mfe is enabled
     """
-    return ENABLE_REACT_MARKDOWN_EDITOR.is_enabled(course_key)
+    return not DISABLE_REACT_MARKDOWN_EDITOR.is_enabled(course_key)
 
 
 # .. toggle_name: legacy_studio.schedule_details