diff --git a/common/djangoapps/student/tests/test_enrollment.py b/common/djangoapps/student/tests/test_enrollment.py
index e453843083..657b4b5b6a 100644
--- a/common/djangoapps/student/tests/test_enrollment.py
+++ b/common/djangoapps/student/tests/test_enrollment.py
@@ -78,7 +78,6 @@ class EnrollmentTest(ModuleStoreTestCase):
                 course_id=self.course.id,
                 mode_slug=mode_slug,
                 mode_display_name=mode_slug,
-                expiration_datetime=datetime.now(pytz.UTC) + timedelta(days=1)
             )
 
         # Reverse the expected next URL, if one is provided
@@ -126,8 +125,7 @@ class EnrollmentTest(ModuleStoreTestCase):
             CourseModeFactory.create(
                 course_id=self.course.id,
                 mode_slug=mode_slug,
-                mode_display_name=mode_slug,
-                expiration_datetime=datetime.now(pytz.UTC) + timedelta(days=1)
+                mode_display_name=mode_slug
             )
 
         # Log out, so we're no longer authenticated
@@ -155,6 +153,31 @@ class EnrollmentTest(ModuleStoreTestCase):
         self.assertIn('auto_register', self.client.session)
         self.assertTrue(self.client.session['auto_register'])
 
+    # TODO (ECOM-16): Remove once the auto-registration A/B test completes
+    def test_enroll_auto_registration_excluded_course(self):
+        # Create the course modes
+        for mode_slug in ['honor', 'audit', 'verified']:
+            CourseModeFactory.create(
+                course_id=self.course.id,
+                mode_slug=mode_slug,
+                mode_display_name=mode_slug,
+            )
+
+        # Visit the experimental condition URL (when the course is NOT excluded)
+        # This should place us into the experimental condition flow
+        self._change_enrollment('enroll', auto_reg=True)
+
+        # Unenroll from the course (we were registered because auto enroll was enabled)
+        self._change_enrollment('unenroll')
+
+        # Register for the course again, with the course excluded
+        # At this point, we should NOT be in the experimental condition flow
+        excluded_course_ids = [self.course.id.to_deprecated_string()]
+        with self.settings(AUTO_REGISTRATION_AB_TEST_EXCLUDE_COURSES=excluded_course_ids):
+            self._change_enrollment('enroll')
+            self.assertFalse(CourseEnrollment.is_enrolled(self.user, self.course.id))
+            self.assertNotIn('auto_register', self.client.session)
+
     def test_unenroll(self):
         # Enroll the student in the course
         CourseEnrollment.enroll(self.user, self.course.id, mode="honor")
diff --git a/common/djangoapps/student/views.py b/common/djangoapps/student/views.py
index 2c8da158f1..087866a6cf 100644
--- a/common/djangoapps/student/views.py
+++ b/common/djangoapps/student/views.py
@@ -619,6 +619,14 @@ def change_enrollment(request, auto_register=False):
         Response
 
     """
+    user = request.user
+
+    action = request.POST.get("enrollment_action")
+    if 'course_id' not in request.POST:
+        return HttpResponseBadRequest(_("Course id not specified"))
+
+    course_id = SlashSeparatedCourseKey.from_deprecated_string(request.POST.get("course_id"))
+
     # TODO (ECOM-16): Remove this once the auto-registration A/B test completes
     # If a user is in the experimental condition (auto-registration enabled),
     # immediately set a session flag so they stay in the experimental condition.
@@ -630,13 +638,13 @@ def change_enrollment(request, auto_register=False):
     if request.session.get('auto_register') and not auto_register:
         auto_register = True
 
-    user = request.user
-
-    action = request.POST.get("enrollment_action")
-    if 'course_id' not in request.POST:
-        return HttpResponseBadRequest(_("Course id not specified"))
-
-    course_id = SlashSeparatedCourseKey.from_deprecated_string(request.POST.get("course_id"))
+    # TODO (ECOM-16): Remove this once the auto-registration A/B test completes
+    # We've agreed to exclude certain courses from the A/B test.  If we find ourselves
+    # registering for one of these courses, immediately switch to the control.
+    if unicode(course_id) in getattr(settings, 'AUTO_REGISTRATION_AB_TEST_EXCLUDE_COURSES', []):
+        auto_register = False
+        if 'auto_register' in request.session:
+            del request.session['auto_register']
 
     if not user.is_authenticated():
         return HttpResponseForbidden()
diff --git a/lms/envs/aws.py b/lms/envs/aws.py
index d26fad116c..9deb623aa6 100644
--- a/lms/envs/aws.py
+++ b/lms/envs/aws.py
@@ -445,3 +445,6 @@ OPTIMIZELY_PROJECT_ID = AUTH_TOKENS.get('OPTIMIZELY_PROJECT_ID', OPTIMIZELY_PROJ
 
 #### Course Registration Code length ####
 REGISTRATION_CODE_LENGTH = ENV_TOKENS.get('REGISTRATION_CODE_LENGTH', 8)
+
+# TODO (ECOM-16): Remove once the A/B test of auto-registration completes
+AUTO_REGISTRATION_AB_TEST_EXCLUDE_COURSES = set(ENV_TOKENS.get('AUTO_REGISTRATION_AB_TEST_EXCLUDE_COURSES', AUTO_REGISTRATION_AB_TEST_EXCLUDE_COURSES))
diff --git a/lms/envs/common.py b/lms/envs/common.py
index 0ca6bd2ffb..cc98c27b81 100644
--- a/lms/envs/common.py
+++ b/lms/envs/common.py
@@ -1729,3 +1729,21 @@ OPENID_DOMAIN_PREFIX = 'openid:'
 ANALYTICS_DATA_URL = ""
 ANALYTICS_DATA_TOKEN = ""
 ANALYTICS_DASHBOARD_URL = ""
+
+# TODO (ECOM-16): Remove once the A/B test of auto-registration completes
+AUTO_REGISTRATION_AB_TEST_EXCLUDE_COURSES = set([
+    "HarvardX/SW12.2x/1T2014",
+    "HarvardX/SW12.3x/1T2014",
+    "HarvardX/SW12.4x/1T2014",
+    "HarvardX/SW12.5x/2T2014",
+    "HarvardX/SW12.6x/2T2014",
+    "HarvardX/HUM2.1x/3T2014",
+    "HarvardX/SW12x/2013_SOND",
+    "LinuxFoundationX/LFS101x/2T2014",
+    "HarvardX/CS50x/2014_T1",
+    "HarvardX/AmPoX.1/2014_T3",
+    "HarvardX/SW12.7x/3T2014",
+    "HarvardX/SW12.10x/1T2015",
+    "HarvardX/SW12.9x/3T2014",
+    "HarvardX/SW12.8x/3T2014",
+])