diff --git a/lms/djangoapps/teams/errors.py b/lms/djangoapps/teams/errors.py
index 36b8ca54a0..0f718d93a6 100644
--- a/lms/djangoapps/teams/errors.py
+++ b/lms/djangoapps/teams/errors.py
@@ -14,3 +14,8 @@ class NotEnrolledInCourseForTeam(TeamAPIRequestError):
 class AlreadyOnTeamInCourse(TeamAPIRequestError):
     """User is already a member of another team in the same course."""
     pass
+
+
+class ImmutableMembershipFieldException(Exception):
+    """An attempt was made to change an immutable field on a CourseTeamMembership model"""
+    pass
diff --git a/lms/djangoapps/teams/migrations/0006_add_team_size.py b/lms/djangoapps/teams/migrations/0006_add_team_size.py
new file mode 100644
index 0000000000..a89c03895c
--- /dev/null
+++ b/lms/djangoapps/teams/migrations/0006_add_team_size.py
@@ -0,0 +1,98 @@
+# -*- coding: utf-8 -*-
+from south.utils import datetime_utils as datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+from teams.models import CourseTeamMembership
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Adding field 'CourseTeam.team_size'
+        db.add_column('teams_courseteam', 'team_size',
+                      self.gf('django.db.models.fields.IntegerField')(default=0, db_index=True),
+                      keep_default=False)
+
+        # Adding index on 'CourseTeam', fields ['last_activity_at']
+        db.create_index('teams_courseteam', ['last_activity_at'])
+
+        if not db.dry_run:
+            for team in orm.CourseTeam.objects.all():
+                team.team_size = CourseTeamMembership.objects.filter(team=team).count()
+                team.save()
+
+    def backwards(self, orm):
+        # Removing index on 'CourseTeam', fields ['last_activity_at']
+        db.delete_index('teams_courseteam', ['last_activity_at'])
+
+        # Deleting field 'CourseTeam.team_size'
+        db.delete_column('teams_courseteam', 'team_size')
+
+
+    models = {
+        'auth.group': {
+            'Meta': {'object_name': 'Group'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '80'}),
+            'permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'})
+        },
+        'auth.permission': {
+            'Meta': {'ordering': "('content_type__app_label', 'content_type__model', 'codename')", 'unique_together': "(('content_type', 'codename'),)", 'object_name': 'Permission'},
+            'codename': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['contenttypes.ContentType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'auth.user': {
+            'Meta': {'object_name': 'User'},
+            'date_joined': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
+            'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'groups': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Group']", 'symmetrical': 'False', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'is_staff': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'is_superuser': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'last_login': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'password': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
+            'user_permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'}),
+            'username': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '30'})
+        },
+        'contenttypes.contenttype': {
+            'Meta': {'ordering': "('name',)", 'unique_together': "(('app_label', 'model'),)", 'object_name': 'ContentType', 'db_table': "'django_content_type'"},
+            'app_label': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'model': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        },
+        'teams.courseteam': {
+            'Meta': {'object_name': 'CourseTeam'},
+            'country': ('django_countries.fields.CountryField', [], {'max_length': '2', 'blank': 'True'}),
+            'course_id': ('xmodule_django.models.CourseKeyField', [], {'max_length': '255', 'db_index': 'True'}),
+            'date_created': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
+            'description': ('django.db.models.fields.CharField', [], {'max_length': '300'}),
+            'discussion_topic_id': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '255'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'language': ('student.models.LanguageField', [], {'max_length': '16', 'blank': 'True'}),
+            'last_activity_at': ('django.db.models.fields.DateTimeField', [], {'db_index': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '255', 'db_index': 'True'}),
+            'team_id': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '255'}),
+            'team_size': ('django.db.models.fields.IntegerField', [], {'default': '0', 'db_index': 'True'}),
+            'topic_id': ('django.db.models.fields.CharField', [], {'db_index': 'True', 'max_length': '255', 'blank': 'True'}),
+            'users': ('django.db.models.fields.related.ManyToManyField', [], {'db_index': 'True', 'related_name': "'teams'", 'symmetrical': 'False', 'through': "orm['teams.CourseTeamMembership']", 'to': "orm['auth.User']"})
+        },
+        'teams.courseteammembership': {
+            'Meta': {'unique_together': "(('user', 'team'),)", 'object_name': 'CourseTeamMembership'},
+            'date_joined': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'last_activity_at': ('django.db.models.fields.DateTimeField', [], {}),
+            'team': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'membership'", 'to': "orm['teams.CourseTeam']"}),
+            'user': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['auth.User']"})
+        }
+    }
+
+    complete_apps = ['teams']
diff --git a/lms/djangoapps/teams/migrations/0007_auto__del_field_courseteam_is_active.py b/lms/djangoapps/teams/migrations/0007_auto__del_field_courseteam_is_active.py
new file mode 100644
index 0000000000..1810468dbe
--- /dev/null
+++ b/lms/djangoapps/teams/migrations/0007_auto__del_field_courseteam_is_active.py
@@ -0,0 +1,85 @@
+# -*- coding: utf-8 -*-
+from south.utils import datetime_utils as datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Deleting field 'CourseTeam.is_active'
+        db.delete_column('teams_courseteam', 'is_active')
+
+
+    def backwards(self, orm):
+        # Adding field 'CourseTeam.is_active'
+        db.add_column('teams_courseteam', 'is_active',
+                      self.gf('django.db.models.fields.BooleanField')(default=True),
+                      keep_default=False)
+
+
+    models = {
+        'auth.group': {
+            'Meta': {'object_name': 'Group'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '80'}),
+            'permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'})
+        },
+        'auth.permission': {
+            'Meta': {'ordering': "('content_type__app_label', 'content_type__model', 'codename')", 'unique_together': "(('content_type', 'codename'),)", 'object_name': 'Permission'},
+            'codename': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['contenttypes.ContentType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'auth.user': {
+            'Meta': {'object_name': 'User'},
+            'date_joined': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
+            'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'groups': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Group']", 'symmetrical': 'False', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'is_staff': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'is_superuser': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'last_login': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'password': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
+            'user_permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'}),
+            'username': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '30'})
+        },
+        'contenttypes.contenttype': {
+            'Meta': {'ordering': "('name',)", 'unique_together': "(('app_label', 'model'),)", 'object_name': 'ContentType', 'db_table': "'django_content_type'"},
+            'app_label': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'model': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        },
+        'teams.courseteam': {
+            'Meta': {'object_name': 'CourseTeam'},
+            'country': ('django_countries.fields.CountryField', [], {'max_length': '2', 'blank': 'True'}),
+            'course_id': ('xmodule_django.models.CourseKeyField', [], {'max_length': '255', 'db_index': 'True'}),
+            'date_created': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
+            'description': ('django.db.models.fields.CharField', [], {'max_length': '300'}),
+            'discussion_topic_id': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '255'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'language': ('student.models.LanguageField', [], {'max_length': '16', 'blank': 'True'}),
+            'last_activity_at': ('django.db.models.fields.DateTimeField', [], {'db_index': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '255', 'db_index': 'True'}),
+            'team_id': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '255'}),
+            'team_size': ('django.db.models.fields.IntegerField', [], {'default': '0', 'db_index': 'True'}),
+            'topic_id': ('django.db.models.fields.CharField', [], {'db_index': 'True', 'max_length': '255', 'blank': 'True'}),
+            'users': ('django.db.models.fields.related.ManyToManyField', [], {'db_index': 'True', 'related_name': "'teams'", 'symmetrical': 'False', 'through': "orm['teams.CourseTeamMembership']", 'to': "orm['auth.User']"})
+        },
+        'teams.courseteammembership': {
+            'Meta': {'unique_together': "(('user', 'team'),)", 'object_name': 'CourseTeamMembership'},
+            'date_joined': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'last_activity_at': ('django.db.models.fields.DateTimeField', [], {}),
+            'team': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'membership'", 'to': "orm['teams.CourseTeam']"}),
+            'user': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['auth.User']"})
+        }
+    }
+
+    complete_apps = ['teams']
\ No newline at end of file
diff --git a/lms/djangoapps/teams/models.py b/lms/djangoapps/teams/models.py
index 8cba347235..e94e76da26 100644
--- a/lms/djangoapps/teams/models.py
+++ b/lms/djangoapps/teams/models.py
@@ -26,7 +26,7 @@ from django_comment_common.signals import (
 from xmodule_django.models import CourseKeyField
 from util.model_utils import slugify
 from student.models import LanguageField, CourseEnrollment
-from .errors import AlreadyOnTeamInCourse, NotEnrolledInCourseForTeam
+from .errors import AlreadyOnTeamInCourse, NotEnrolledInCourseForTeam, ImmutableMembershipFieldException
 from teams import TEAM_DISCUSSION_CONTEXT
 
 
@@ -76,7 +76,6 @@ class CourseTeam(models.Model):
     team_id = models.CharField(max_length=255, unique=True)
     discussion_topic_id = models.CharField(max_length=255, unique=True)
     name = models.CharField(max_length=255, db_index=True)
-    is_active = models.BooleanField(default=True)
     course_id = CourseKeyField(max_length=255, db_index=True)
     topic_id = models.CharField(max_length=255, db_index=True, blank=True)
     date_created = models.DateTimeField(auto_now_add=True)
@@ -86,8 +85,9 @@ class CourseTeam(models.Model):
         blank=True,
         help_text=ugettext_lazy("Optional language the team uses as ISO 639-1 code."),
     )
-    last_activity_at = models.DateTimeField()
+    last_activity_at = models.DateTimeField(db_index=True)  # indexed for ordering
     users = models.ManyToManyField(User, db_index=True, related_name='teams', through='CourseTeamMembership')
+    team_size = models.IntegerField(default=0, db_index=True)  # indexed for ordering
 
     @classmethod
     def create(cls, name, course_id, description, topic_id=None, country=None, language=None):
@@ -135,6 +135,11 @@ class CourseTeam(models.Model):
             team=self
         )
 
+    def reset_team_size(self):
+        """Reset team_size to reflect the current membership count."""
+        self.team_size = CourseTeamMembership.objects.filter(team=self).count()
+        self.save()
+
 
 class CourseTeamMembership(models.Model):
     """This model represents the membership of a single user in a single team."""
@@ -148,12 +153,40 @@ class CourseTeamMembership(models.Model):
     date_joined = models.DateTimeField(auto_now_add=True)
     last_activity_at = models.DateTimeField()
 
+    immutable_fields = ('user', 'team', 'date_joined')
+
+    def __setattr__(self, name, value):
+        """Memberships are immutable, with the exception of last activity
+        date.
+        """
+        if name in self.immutable_fields:
+            # Check the current value -- if it is None, then this
+            # model is being created from the database and it's fine
+            # to set the value. Otherwise, we're trying to overwrite
+            # an immutable field.
+            current_value = getattr(self, name, None)
+            if current_value is not None:
+                raise ImmutableMembershipFieldException
+        super(CourseTeamMembership, self).__setattr__(name, value)
+
     def save(self, *args, **kwargs):
-        """ Customize save method to set the last_activity_at if it does not currently exist. """
+        """Customize save method to set the last_activity_at if it does not
+        currently exist. Also resets the team's size if this model is
+        being created.
+        """
+        should_reset_team_size = False
+        if self.pk is None:
+            should_reset_team_size = True
         if not self.last_activity_at:
             self.last_activity_at = datetime.utcnow().replace(tzinfo=pytz.utc)
-
         super(CourseTeamMembership, self).save(*args, **kwargs)
+        if should_reset_team_size:
+            self.team.reset_team_size()  # pylint: disable=no-member
+
+    def delete(self, *args, **kwargs):
+        """Recompute the related team's team_size after deleting a membership"""
+        super(CourseTeamMembership, self).delete(*args, **kwargs)
+        self.team.reset_team_size()  # pylint: disable=no-member
 
     @classmethod
     def get_memberships(cls, username=None, course_ids=None, team_id=None):
diff --git a/lms/djangoapps/teams/serializers.py b/lms/djangoapps/teams/serializers.py
index 7f403c2957..79183e464c 100644
--- a/lms/djangoapps/teams/serializers.py
+++ b/lms/djangoapps/teams/serializers.py
@@ -51,7 +51,6 @@ class CourseTeamSerializer(serializers.ModelSerializer):
             "id",
             "discussion_topic_id",
             "name",
-            "is_active",
             "course_id",
             "topic_id",
             "date_created",
diff --git a/lms/djangoapps/teams/static/teams/js/models/team.js b/lms/djangoapps/teams/static/teams/js/models/team.js
index f8771f6e80..3ee13b53ae 100644
--- a/lms/djangoapps/teams/static/teams/js/models/team.js
+++ b/lms/djangoapps/teams/static/teams/js/models/team.js
@@ -8,7 +8,6 @@
             defaults: {
                 id: null,
                 name: '',
-                is_active: null,
                 course_id: '',
                 topic_id: '',
                 date_created: '',
diff --git a/lms/djangoapps/teams/static/teams/js/spec/views/edit_team_spec.js b/lms/djangoapps/teams/static/teams/js/spec/views/edit_team_spec.js
index 5a68d3163b..97c959000c 100644
--- a/lms/djangoapps/teams/static/teams/js/spec/views/edit_team_spec.js
+++ b/lms/djangoapps/teams/static/teams/js/spec/views/edit_team_spec.js
@@ -14,7 +14,6 @@ define([
             createTeamData = {
                 id: null,
                 name: "TeamName",
-                is_active: null,
                 course_id: "a/b/c",
                 topic_id: "awesomeness",
                 date_created: "",
diff --git a/lms/djangoapps/teams/static/teams/js/spec_helpers/team_spec_helpers.js b/lms/djangoapps/teams/static/teams/js/spec_helpers/team_spec_helpers.js
index a210bf7c4e..08d3ada6ba 100644
--- a/lms/djangoapps/teams/static/teams/js/spec_helpers/team_spec_helpers.js
+++ b/lms/djangoapps/teams/static/teams/js/spec_helpers/team_spec_helpers.js
@@ -32,7 +32,6 @@ define([
                 id: "id " + i,
                 language: testLanguages[i%4][0],
                 country: testCountries[i%4][0],
-                is_active: true,
                 membership: [],
                 last_activity_at: ''
             };
diff --git a/lms/djangoapps/teams/tests/test_models.py b/lms/djangoapps/teams/tests/test_models.py
index 39c645dd78..ba9fc6f53c 100644
--- a/lms/djangoapps/teams/tests/test_models.py
+++ b/lms/djangoapps/teams/tests/test_models.py
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+# pylint: disable=no-member
 """Tests for the teams API at the HTTP request level."""
 from contextlib import contextmanager
 from datetime import datetime
@@ -20,7 +21,7 @@ from django_comment_common.signals import (
 )
 from xmodule.modulestore.tests.django_utils import SharedModuleStoreTestCase
 from opaque_keys.edx.keys import CourseKey
-from student.tests.factories import UserFactory
+from student.tests.factories import CourseEnrollmentFactory, UserFactory
 
 from .factories import CourseTeamFactory, CourseTeamMembershipFactory
 from ..models import CourseTeam, CourseTeamMembership
@@ -42,16 +43,18 @@ class TeamMembershipTest(SharedModuleStoreTestCase):
 
         self.user1 = UserFactory.create(username='user1')
         self.user2 = UserFactory.create(username='user2')
+        self.user3 = UserFactory.create(username='user3')
+
+        for user in (self.user1, self.user2, self.user3):
+            CourseEnrollmentFactory.create(user=user, course_id=COURSE_KEY1)
+        CourseEnrollmentFactory.create(user=self.user1, course_id=COURSE_KEY2)
 
         self.team1 = CourseTeamFactory(course_id=COURSE_KEY1, team_id='team1')
         self.team2 = CourseTeamFactory(course_id=COURSE_KEY2, team_id='team2')
 
-        self.team_membership11 = CourseTeamMembership(user=self.user1, team=self.team1)
-        self.team_membership11.save()
-        self.team_membership12 = CourseTeamMembership(user=self.user2, team=self.team1)
-        self.team_membership12.save()
-        self.team_membership21 = CourseTeamMembership(user=self.user1, team=self.team2)
-        self.team_membership21.save()
+        self.team_membership11 = self.team1.add_user(self.user1)
+        self.team_membership12 = self.team1.add_user(self.user2)
+        self.team_membership21 = self.team2.add_user(self.user1)
 
     def test_membership_last_activity_set(self):
         current_last_activity = self.team_membership11.last_activity_at
@@ -64,6 +67,24 @@ class TeamMembershipTest(SharedModuleStoreTestCase):
         # already exist.
         self.assertEqual(self.team_membership11.last_activity_at, current_last_activity)
 
+    def test_team_size_delete_membership(self):
+        """Test that the team size field is correctly updated when deleting a
+        team membership.
+        """
+        self.assertEqual(self.team1.team_size, 2)
+        self.team_membership11.delete()
+        team = CourseTeam.objects.get(id=self.team1.id)
+        self.assertEqual(team.team_size, 1)
+
+    def test_team_size_create_membership(self):
+        """Test that the team size field is correctly updated when creating a
+        team membership.
+        """
+        self.assertEqual(self.team1.team_size, 2)
+        self.team1.add_user(self.user3)
+        team = CourseTeam.objects.get(id=self.team1.id)
+        self.assertEqual(team.team_size, 3)
+
     @ddt.data(
         (None, None, None, 3),
         ('user1', None, None, 2),
diff --git a/lms/djangoapps/teams/tests/test_views.py b/lms/djangoapps/teams/tests/test_views.py
index 1f24835c82..8b61630c93 100644
--- a/lms/djangoapps/teams/tests/test_views.py
+++ b/lms/djangoapps/teams/tests/test_views.py
@@ -208,13 +208,8 @@ class TeamAPITestCase(APITestCase, SharedModuleStoreTestCase):
             )
             self.test_team_2 = CourseTeamFactory.create(name='Wind Team', course_id=self.test_course_1.id)
             self.test_team_3 = CourseTeamFactory.create(name='Nuclear Team', course_id=self.test_course_1.id)
-            self.test_team_4 = CourseTeamFactory.create(
-                name='Coal Team',
-                course_id=self.test_course_1.id,
-                is_active=False
-            )
-            self.test_team_5 = CourseTeamFactory.create(name='Another Team', course_id=self.test_course_2.id)
-            self.test_team_6 = CourseTeamFactory.create(
+            self.test_team_4 = CourseTeamFactory.create(name='Another Team', course_id=self.test_course_2.id)
+            self.test_team_5 = CourseTeamFactory.create(
                 name='Public Profile Team',
                 course_id=self.test_course_2.id,
                 topic_id='topic_6'
@@ -234,7 +229,6 @@ class TeamAPITestCase(APITestCase, SharedModuleStoreTestCase):
             self.test_team_3,
             self.test_team_4,
             self.test_team_5,
-            self.test_team_6,
             self.test_team_7,
         )}
 
@@ -245,8 +239,8 @@ class TeamAPITestCase(APITestCase, SharedModuleStoreTestCase):
 
         self.test_team_1.add_user(self.users['student_enrolled'])
         self.test_team_3.add_user(self.users['student_enrolled_both_courses_other_team'])
-        self.test_team_5.add_user(self.users['student_enrolled_both_courses_other_team'])
-        self.test_team_6.add_user(self.users['student_enrolled_public_profile'])
+        self.test_team_4.add_user(self.users['student_enrolled_both_courses_other_team'])
+        self.test_team_5.add_user(self.users['student_enrolled_public_profile'])
 
     def build_membership_data_raw(self, username, team):
         """Assembles a membership creation payload based on the raw values provided."""
@@ -400,7 +394,7 @@ class TeamAPITestCase(APITestCase, SharedModuleStoreTestCase):
 
     def verify_expanded_team(self, team):
         """Verifies that fields exist on the returned team json indicating that it is expanded."""
-        for field in ['id', 'name', 'is_active', 'course_id', 'topic_id', 'date_created', 'description']:
+        for field in ['id', 'name', 'course_id', 'topic_id', 'date_created', 'description']:
             self.assertIn(field, team)
 
 
@@ -446,9 +440,6 @@ class TestListTeamsAPI(TeamAPITestCase):
     def test_filter_topic_id(self):
         self.verify_names({'course_id': self.test_course_1.id, 'topic_id': 'topic_0'}, 200, [u'Sólar team'])
 
-    def test_filter_include_inactive(self):
-        self.verify_names({'include_inactive': True}, 200, ['Coal Team', 'Nuclear Team', u'Sólar team', 'Wind Team'])
-
     @ddt.data(
         (None, 200, ['Nuclear Team', u'Sólar team', 'Wind Team']),
         ('name', 200, ['Nuclear Team', u'Sólar team', 'Wind Team']),
@@ -673,7 +664,6 @@ class TestCreateTeamAPI(TeamAPITestCase):
             'name': 'Fully specified team',
             'language': 'fr',
             'country': 'CA',
-            'is_active': True,
             'topic_id': 'great-topic',
             'course_id': str(self.test_course_1.id),
             'description': 'Another fantastic team'
@@ -723,7 +713,7 @@ class TestDetailTeamAPI(TeamAPITestCase):
 
     def test_expand_public_user(self):
         result = self.get_team_detail(
-            self.test_team_6.team_id,
+            self.test_team_5.team_id,
             200,
             {'expand': 'user'},
             user='student_enrolled_public_profile'
@@ -1025,7 +1015,7 @@ class TestListMembershipAPI(TeamAPITestCase):
     def test_expand_public_user(self):
         result = self.get_membership_list(
             200,
-            {'team_id': self.test_team_6.team_id, 'expand': 'user'},
+            {'team_id': self.test_team_5.team_id, 'expand': 'user'},
             user='student_enrolled_public_profile'
         )
         self.verify_expanded_public_user(result['results'][0]['user'])
@@ -1113,7 +1103,7 @@ class TestCreateMembershipAPI(TeamAPITestCase):
     def test_over_max_team_size_in_course_2(self):
         response = self.post_create_membership(
             400,
-            self.build_membership_data('student_enrolled_other_course_not_on_team', self.test_team_5),
+            self.build_membership_data('student_enrolled_other_course_not_on_team', self.test_team_4),
             user='student_enrolled_other_course_not_on_team'
         )
         self.assertIn('full', json.loads(response.content)['developer_message'])
@@ -1167,7 +1157,7 @@ class TestDetailMembershipAPI(TeamAPITestCase):
 
     def test_expand_public_user(self):
         result = self.get_membership_detail(
-            self.test_team_6.team_id,
+            self.test_team_5.team_id,
             self.users['student_enrolled_public_profile'].username,
             200,
             {'expand': 'user'},
diff --git a/lms/djangoapps/teams/views.py b/lms/djangoapps/teams/views.py
index 87cf06a3b3..4dbb72dfa0 100644
--- a/lms/djangoapps/teams/views.py
+++ b/lms/djangoapps/teams/views.py
@@ -191,9 +191,6 @@ class TeamsListView(ExpandableFieldViewMixin, GenericAPIView):
 
             * page: Page number to retrieve.
 
-            * include_inactive: If true, inactive teams will be returned. The
-              default is to not include inactive teams.
-
             * expand: Comma separated list of types for which to return
               expanded representations. Supports "user" and "team".
 
@@ -220,10 +217,6 @@ class TeamsListView(ExpandableFieldViewMixin, GenericAPIView):
 
                 * name: The name of the team.
 
-                * is_active: True if the team is currently active. If false, the
-                  team is considered "soft deleted" and will not be included by
-                  default in results.
-
                 * course_id: The identifier for the course this team belongs to.
 
                 * topic_id: Optionally specifies which topic the team is associated
@@ -266,8 +259,8 @@ class TeamsListView(ExpandableFieldViewMixin, GenericAPIView):
 
             Any logged in user who has verified their email address can create
             a team. The format mirrors that of a GET for an individual team,
-            but does not include the id, is_active, date_created, or membership
-            fields. id is automatically computed based on name.
+            but does not include the id, date_created, or membership fields.
+            id is automatically computed based on name.
 
             If the user is not logged in, a 401 error is returned.
 
@@ -292,9 +285,7 @@ class TeamsListView(ExpandableFieldViewMixin, GenericAPIView):
 
     def get(self, request):
         """GET /api/team/v0/teams/"""
-        result_filter = {
-            'is_active': True
-        }
+        result_filter = {}
 
         if 'course_id' in request.QUERY_PARAMS:
             course_id_string = request.QUERY_PARAMS['course_id']
@@ -335,8 +326,6 @@ class TeamsListView(ExpandableFieldViewMixin, GenericAPIView):
                 )
                 return Response(error, status=status.HTTP_400_BAD_REQUEST)
             result_filter.update({'topic_id': request.QUERY_PARAMS['topic_id']})
-        if 'include_inactive' in request.QUERY_PARAMS and request.QUERY_PARAMS['include_inactive'].lower() == 'true':
-            del result_filter['is_active']
 
         if 'text_search' in request.QUERY_PARAMS and CourseTeamIndexer.search_is_enabled():
             search_engine = CourseTeamIndexer.engine()
@@ -355,7 +344,6 @@ class TeamsListView(ExpandableFieldViewMixin, GenericAPIView):
                 self.get_paginate_by(),
                 self.get_page()
             )
-
             serializer = self.get_pagination_serializer(paginated_results)
         else:
             queryset = CourseTeam.objects.filter(**result_filter)
@@ -364,10 +352,8 @@ class TeamsListView(ExpandableFieldViewMixin, GenericAPIView):
                 # MySQL does case-insensitive order_by.
                 queryset = queryset.order_by('name')
             elif order_by_input == 'open_slots':
-                queryset = queryset.annotate(team_size=Count('users'))
                 queryset = queryset.order_by('team_size', '-last_activity_at')
             elif order_by_input == 'last_activity_at':
-                queryset = queryset.annotate(team_size=Count('users'))
                 queryset = queryset.order_by('-last_activity_at', 'team_size')
             else:
                 return Response({
@@ -496,10 +482,6 @@ class TeamsDetailView(ExpandableFieldViewMixin, RetrievePatchAPIView):
 
                 * name: The name of the team.
 
-                * is_active: True if the team is currently active. If false, the team
-                  is considered "soft deleted" and will not be included by default in
-                  results.
-
                 * course_id: The identifier for the course this team belongs to.
 
                 * topic_id: Optionally specifies which topic the team is