diff --git a/lms/static/js/groups/views/cohort_editor.js b/lms/static/js/groups/views/cohort_editor.js
index feb451328174..9da4a0c92a65 100644
--- a/lms/static/js/groups/views/cohort_editor.js
+++ b/lms/static/js/groups/views/cohort_editor.js
@@ -260,16 +260,17 @@
 
                     // Show error messages.
                     this.undelegateViewEvents(this.errorNotifications);
-                    numErrors = modifiedUsers.unknown.length + modifiedUsers.invalid.length;
+                    numErrors = modifiedUsers.unknown.length + modifiedUsers.invalid.length + modifiedUsers.not_allowed.length;
                     if (numErrors > 0) {
-                        createErrorDetails = function(unknownUsers, invalidEmails, showAllErrors) {
+                        createErrorDetails = function(unknownUsers, invalidEmails, notAllowed, showAllErrors) {
                             var unknownErrorsShown = showAllErrors ? unknownUsers.length :
                                 Math.min(errorLimit, unknownUsers.length);
                             var invalidErrorsShown = showAllErrors ? invalidEmails.length :
                                 Math.min(errorLimit - unknownUsers.length, invalidEmails.length);
+                            var notAllowedErrorsShown = showAllErrors ? notAllowed.length :
+                                Math.min(errorLimit - notAllowed.length, notAllowed.length);
                             details = [];
 
-
                             for (i = 0; i < unknownErrorsShown; i++) {
                                 details.push(interpolate_text(gettext('Unknown username: {user}'),
                                     {user: unknownUsers[i]}));
@@ -278,6 +279,10 @@
                                 details.push(interpolate_text(gettext('Invalid email address: {email}'),
                                     {email: invalidEmails[i]}));
                             }
+                            for (i = 0; i < notAllowedErrorsShown; i++) {
+                                details.push(interpolate_text(gettext('Cohort assignment not allowed: {email_or_username}'),
+                                    {email_or_username: notAllowed[i]}));
+                            }
                             return details;
                         };
 
@@ -286,12 +291,12 @@
                                 '{numErrors} learners could not be added to this cohort:', numErrors),
                             {numErrors: numErrors}
                         );
-                        details = createErrorDetails(modifiedUsers.unknown, modifiedUsers.invalid, false);
+                        details = createErrorDetails(modifiedUsers.unknown, modifiedUsers.invalid, modifiedUsers.not_allowed, false);
 
                         errorActionCallback = function(view) {
                             view.model.set('actionText', null);
                             view.model.set('details',
-                                createErrorDetails(modifiedUsers.unknown, modifiedUsers.invalid, true));
+                                createErrorDetails(modifiedUsers.unknown, modifiedUsers.invalid, modifiedUsers.not_allowed, true));
                             view.render();
                         };
 
diff --git a/lms/static/js/spec/groups/views/cohorts_spec.js b/lms/static/js/spec/groups/views/cohorts_spec.js
index 709930814ba6..51579701b5fb 100644
--- a/lms/static/js/spec/groups/views/cohorts_spec.js
+++ b/lms/static/js/spec/groups/views/cohorts_spec.js
@@ -14,6 +14,7 @@ define(['backbone', 'jquery', 'edx-ui-toolkit/js/utils/spec-helpers/ajax-helpers
             var catLoversInitialCount = 123,
                 dogLoversInitialCount = 456,
                 unknownUserMessage,
+                notAllowedUserMessage,
                 invalidEmailMessage, createMockCohort, createMockCohorts, createMockContentGroups,
                 createMockCohortSettingsJson,
                 createCohortsView, cohortsView, requests, respondToRefresh, verifyMessage, verifyNoMessage,
@@ -210,6 +211,10 @@ define(['backbone', 'jquery', 'edx-ui-toolkit/js/utils/spec-helpers/ajax-helpers
                 return 'Invalid email address: ' + name;
             };
 
+            notAllowedUserMessage = function(email) {
+                return 'Cohort assignment not allowed: ' + email;
+            };
+
             beforeEach(function() {
                 setFixtures('<ul class="instructor-nav">' +
                     '<li class="nav-item"><button type="button" data-section="cohort_management" ' +
@@ -602,7 +607,7 @@ define(['backbone', 'jquery', 'edx-ui-toolkit/js/utils/spec-helpers/ajax-helpers
                 respondToAdd = function(result) {
                     AjaxHelpers.respondWithJson(
                         requests,
-                        _.extend({unknown: [], added: [], present: [], changed: [],
+                        _.extend({unknown: [], added: [], present: [], changed: [], not_allowed: [],
                             success: true, preassigned: [], invalid: []}, result)
                     );
                 };
@@ -670,6 +675,19 @@ define(['backbone', 'jquery', 'edx-ui-toolkit/js/utils/spec-helpers/ajax-helpers
                     );
                 });
 
+                it('shows an error when user assignment not allowed', function() {
+                    createCohortsView(this, {selectCohort: 1});
+                    addStudents('not_allowed');
+                    AjaxHelpers.expectRequest(
+                        requests, 'POST', '/mock_service/cohorts/1/add', 'users=not_allowed'
+                    );
+                    respondToAdd({not_allowed: ['not_allowed']});
+                    respondToRefresh(catLoversInitialCount, dogLoversInitialCount);
+                    verifyHeader(1, 'Cat Lovers', catLoversInitialCount);
+                    verifyDetailedMessage('There was an error when trying to add learners:', 'error',
+                        [notAllowedUserMessage('not_allowed')]
+                    );
+                });
 
                 it('shows a "view all" button when more than 5 students do not exist', function() {
                     var sixUsers = 'unknown1, unknown2, unknown3, unknown4, unknown5, unknown6';
diff --git a/openedx/core/djangoapps/course_groups/models.py b/openedx/core/djangoapps/course_groups/models.py
index ae7bc15da956..e4dd769824c9 100644
--- a/openedx/core/djangoapps/course_groups/models.py
+++ b/openedx/core/djangoapps/course_groups/models.py
@@ -13,7 +13,7 @@
 from django.dispatch import receiver
 
 from opaque_keys.edx.django.models import CourseKeyField
-from openedx_filters.learning.filters import CohortChangeRequested
+from openedx_filters.learning.filters import CohortAssignmentRequested, CohortChangeRequested
 
 from openedx.core.djangolib.model_mixins import DeletableByUserValue
 
@@ -31,6 +31,10 @@ class CohortChangeNotAllowed(CohortMembershipException):
     pass
 
 
+class CohortAssignmentNotAllowed(CohortMembershipException):
+    pass
+
+
 class CourseUserGroup(models.Model):
     """
     This model represents groups of users in a course.  Groups may have different types,
@@ -113,6 +117,13 @@ def assign(cls, cohort, user):
         cohort
         Returns CohortMembership, previous_cohort (if any)
         """
+        try:
+            # .. filter_implemented_name: CohortAssignmentRequested
+            # .. filter_type: org.openedx.learning.cohort.assignment.requested.v1
+            user, cohort = CohortAssignmentRequested.run_filter(user=user, target_cohort=cohort)
+        except CohortAssignmentRequested.PreventCohortAssignment as exc:
+            raise CohortAssignmentNotAllowed(str(exc)) from exc
+
         with transaction.atomic():
             membership, created = cls.objects.select_for_update().get_or_create(
                 user__id=user.id,
diff --git a/openedx/core/djangoapps/course_groups/tests/test_filters.py b/openedx/core/djangoapps/course_groups/tests/test_filters.py
index d7e8d1b34bab..f51818d676bf 100755
--- a/openedx/core/djangoapps/course_groups/tests/test_filters.py
+++ b/openedx/core/djangoapps/course_groups/tests/test_filters.py
@@ -3,12 +3,16 @@
 """
 from django.test import override_settings
 from openedx_filters import PipelineStep
-from openedx_filters.learning.filters import CohortChangeRequested
+from openedx_filters.learning.filters import CohortAssignmentRequested, CohortChangeRequested
 from xmodule.modulestore.tests.django_utils import SharedModuleStoreTestCase
 
 from common.djangoapps.student.tests.factories import UserFactory
 from openedx.core.djangoapps.content.course_overviews.tests.factories import CourseOverviewFactory
-from openedx.core.djangoapps.course_groups.models import CohortChangeNotAllowed, CohortMembership
+from openedx.core.djangoapps.course_groups.models import (
+    CohortAssignmentNotAllowed,
+    CohortChangeNotAllowed,
+    CohortMembership,
+)
 from openedx.core.djangoapps.course_groups.tests.helpers import CohortFactory
 from openedx.core.djangolib.testing.utils import skip_unless_lms
 
@@ -31,6 +35,23 @@ def run_filter(self, current_membership, target_cohort):  # pylint: disable=argu
         return {}
 
 
+class TestCohortAssignmentStep(PipelineStep):
+    """
+    Utility function used when getting steps for pipeline.
+    """
+
+    def run_filter(self, user, target_cohort):  # pylint: disable=arguments-differ
+        """Pipeline step that adds cohort info to the users profile."""
+        user.profile.set_meta(
+            {
+                "cohort_info":
+                f"User assigned to Cohort {str(target_cohort)}",
+            }
+        )
+        user.profile.save()
+        return {}
+
+
 class TestStopCohortChangeStep(PipelineStep):
     """
     Utility function used when getting steps for pipeline.
@@ -41,6 +62,16 @@ def run_filter(self, current_membership, target_cohort, *args, **kwargs):  # pyl
         raise CohortChangeRequested.PreventCohortChange("You can't change cohorts.")
 
 
+class TestStopAssignmentChangeStep(PipelineStep):
+    """
+    Utility function used when getting steps for pipeline.
+    """
+
+    def run_filter(self, user, target_cohort, *args, **kwargs):  # pylint: disable=arguments-differ
+        """Pipeline step that stops the cohort change process."""
+        raise CohortAssignmentRequested.PreventCohortAssignment("You can't be assign to this cohort.")
+
+
 @skip_unless_lms
 class CohortFiltersTest(SharedModuleStoreTestCase):
     """
@@ -92,6 +123,33 @@ def test_cohort_change_filter_executed(self):
             cohort_membership.user.profile.get_meta(),
         )
 
+    @override_settings(
+        OPEN_EDX_FILTERS_CONFIG={
+            "org.openedx.learning.cohort.assignment.requested.v1": {
+                "pipeline": [
+                    "openedx.core.djangoapps.course_groups.tests.test_filters.TestCohortAssignmentStep",
+                ],
+                "fail_silently": False,
+            },
+        },
+    )
+    def test_cohort_assignment_filter_executed(self):
+        """
+        Test whether the student cohort assignment filter is triggered before the user's
+        assignment.
+
+        Expected result:
+            - CohortAssignmentRequested is triggered and executes TestCohortAssignmentStep.
+            - The user's profile meta contains cohort_info.
+        """
+
+        cohort_membership, _ = CohortMembership.assign(user=self.user, cohort=self.second_cohort, )
+
+        self.assertEqual(
+            {"cohort_info": "User assigned to Cohort SecondCohort"},
+            cohort_membership.user.profile.get_meta(),
+        )
+
     @override_settings(
         OPEN_EDX_FILTERS_CONFIG={
             "org.openedx.learning.cohort.change.requested.v1": {
@@ -115,6 +173,27 @@ def test_cohort_change_filter_prevent_move(self):
         with self.assertRaises(CohortChangeNotAllowed):
             CohortMembership.assign(cohort=self.second_cohort, user=self.user)
 
+    @override_settings(
+        OPEN_EDX_FILTERS_CONFIG={
+            "org.openedx.learning.cohort.assignment.requested.v1": {
+                "pipeline": [
+                    "openedx.core.djangoapps.course_groups.tests.test_filters.TestStopAssignmentChangeStep",
+                ],
+                "fail_silently": False,
+            },
+        },
+    )
+    def test_cohort_assignment_filter_prevent_move(self):
+        """
+        Test prevent the user's cohort assignment through a pipeline step.
+
+        Expected result:
+            - CohortAssignmentRequested is triggered and executes TestStopAssignmentChangeStep.
+            - The user can't be assigned to the cohort.
+        """
+        with self.assertRaises(CohortAssignmentNotAllowed):
+            CohortMembership.assign(cohort=self.second_cohort, user=self.user)
+
     @override_settings(OPEN_EDX_FILTERS_CONFIG={})
     def test_cohort_change_without_filter_configuration(self):
         """
@@ -129,3 +208,16 @@ def test_cohort_change_without_filter_configuration(self):
         cohort_membership, _ = CohortMembership.assign(cohort=self.second_cohort, user=self.user)
 
         self.assertEqual({}, cohort_membership.user.profile.get_meta())
+
+    @override_settings(OPEN_EDX_FILTERS_CONFIG={})
+    def test_cohort_assignment_without_filter_configuration(self):
+        """
+        Test usual cohort assignment process, without filter's intervention.
+
+        Expected result:
+            - CohortAssignmentRequested does not have any effect on the cohort change process.
+            - The cohort assignment process ends successfully.
+        """
+        cohort_membership, _ = CohortMembership.assign(cohort=self.second_cohort, user=self.user)
+
+        self.assertEqual({}, cohort_membership.user.profile.get_meta())
diff --git a/openedx/core/djangoapps/course_groups/views.py b/openedx/core/djangoapps/course_groups/views.py
index 606e5c617dc5..da66240e74b9 100644
--- a/openedx/core/djangoapps/course_groups/views.py
+++ b/openedx/core/djangoapps/course_groups/views.py
@@ -26,7 +26,11 @@
 
 from lms.djangoapps.courseware.courses import get_course, get_course_with_access
 from common.djangoapps.edxmako.shortcuts import render_to_response
-from openedx.core.djangoapps.course_groups.models import CohortMembership
+from openedx.core.djangoapps.course_groups.models import (
+    CohortAssignmentNotAllowed,
+    CohortChangeNotAllowed,
+    CohortMembership,
+)
 from openedx.core.djangoapps.course_groups.permissions import IsStaffOrAdmin
 from openedx.core.lib.api.authentication import BearerAuthenticationAllowInactiveUser
 from openedx.core.lib.api.view_utils import DeveloperErrorViewMixin
@@ -321,6 +325,7 @@ def add_users_to_cohort(request, course_key_string, cohort_id):
     unknown = []
     preassigned = []
     invalid = []
+    not_allowed = []
     for username_or_email in split_by_comma_and_whitespace(users):
         if not username_or_email:
             continue
@@ -346,6 +351,8 @@ def add_users_to_cohort(request, course_key_string, cohort_id):
             invalid.append(username_or_email)
         except ValueError:
             present.append(username_or_email)
+        except (CohortAssignmentNotAllowed, CohortChangeNotAllowed):
+            not_allowed.append(username_or_email)
 
     return json_http_response({'success': True,
                                'added': added,
@@ -353,7 +360,8 @@ def add_users_to_cohort(request, course_key_string, cohort_id):
                                'present': present,
                                'unknown': unknown,
                                'preassigned': preassigned,
-                               'invalid': invalid})
+                               'invalid': invalid,
+                               'not_allowed': not_allowed})
 
 
 @ensure_csrf_cookie