diff --git a/app/assets/javascripts/admin/controllers/admin-group.js.es6 b/app/assets/javascripts/admin/controllers/admin-group.js.es6
index dee7c45bb84..f16151ed29e 100644
--- a/app/assets/javascripts/admin/controllers/admin-group.js.es6
+++ b/app/assets/javascripts/admin/controllers/admin-group.js.es6
@@ -27,6 +27,13 @@ export default Ember.Controller.extend({
     ];
   }.property(),
 
+  trustLevelOptions: function() {
+    return [
+      { name: I18n.t("groups.trust_levels.none"), value: 0 },
+      { name: 1, value: 1 }, { name: 2, value: 2 }, { name: 3, value: 3 }, { name: 4, value: 4 }
+    ];
+  }.property(),
+
   actions: {
     next() {
       if (this.get("showingLast")) { return; }
diff --git a/app/assets/javascripts/admin/templates/group.hbs b/app/assets/javascripts/admin/templates/group.hbs
index 6260d12aab3..3da80d9af7d 100644
--- a/app/assets/javascripts/admin/templates/group.hbs
+++ b/app/assets/javascripts/admin/templates/group.hbs
@@ -70,6 +70,11 @@
       </label>
         {{input value=model.title}}
     </div>
+
+    <div>
+      <label for="grant_trust_level">{{i18n 'groups.trust_levels.title'}}</label>
+      {{combo-box name="grant_trust_level" valueAttribute="value" value=model.grant_trust_level content=trustLevelOptions}}
+    </div>
   {{/unless}}
 
   <div class='buttons'>
diff --git a/app/assets/javascripts/discourse/models/group.js.es6 b/app/assets/javascripts/discourse/models/group.js.es6
index b79db164f48..f90aee368dd 100644
--- a/app/assets/javascripts/discourse/models/group.js.es6
+++ b/app/assets/javascripts/discourse/models/group.js.es6
@@ -62,7 +62,8 @@ const Group = Discourse.Model.extend({
       automatic_membership_email_domains: this.get('emailDomains'),
       automatic_membership_retroactive: !!this.get('automatic_membership_retroactive'),
       title: this.get('title'),
-      primary_group: !!this.get('primary_group')
+      primary_group: !!this.get('primary_group'),
+      grant_trust_level: this.get('grant_trust_level')
     };
   },
 
diff --git a/app/controllers/admin/groups_controller.rb b/app/controllers/admin/groups_controller.rb
index 42ed206bfdb..35f3295d273 100644
--- a/app/controllers/admin/groups_controller.rb
+++ b/app/controllers/admin/groups_controller.rb
@@ -37,6 +37,8 @@ class Admin::GroupsController < Admin::AdminController
   def save_group(group)
     group.alias_level = params[:alias_level].to_i if params[:alias_level].present?
     group.visible = params[:visible] == "true"
+    grant_trust_level = params[:grant_trust_level].to_i
+    group.grant_trust_level = (grant_trust_level > 0 && grant_trust_level <= 4) ? grant_trust_level : nil
 
     group.automatic_membership_email_domains = params[:automatic_membership_email_domains] unless group.automatic
     group.automatic_membership_retroactive = params[:automatic_membership_retroactive] == "true" unless group.automatic
diff --git a/app/models/group.rb b/app/models/group.rb
index b36f5cee20d..bdd3ca82e31 100644
--- a/app/models/group.rb
+++ b/app/models/group.rb
@@ -372,6 +372,7 @@ end
 #  visible                            :boolean          default(TRUE), not null
 #  automatic_membership_email_domains :text
 #  automatic_membership_retroactive   :boolean          default(FALSE)
+#  grant_trust_level                  :integer
 #
 # Indexes
 #
diff --git a/app/models/group_user.rb b/app/models/group_user.rb
index 38351f52b1e..5febb87f3b7 100644
--- a/app/models/group_user.rb
+++ b/app/models/group_user.rb
@@ -8,6 +8,8 @@ class GroupUser < ActiveRecord::Base
   after_save :set_primary_group
   after_destroy :remove_primary_group
 
+  after_save :grant_trust_level
+
   protected
 
   def set_primary_group
@@ -44,6 +46,15 @@ class GroupUser < ActiveRecord::Base
                           title: group.title)
     end
   end
+
+  def grant_trust_level
+    return if group.grant_trust_level.nil?
+    if user.trust_level < group.grant_trust_level
+      user.change_trust_level!(group.grant_trust_level)
+      user.trust_level_locked = true
+      user.save
+    end
+  end
 end
 
 # == Schema Information
diff --git a/app/serializers/basic_group_serializer.rb b/app/serializers/basic_group_serializer.rb
index 9f6ad6b7a2f..38644aff4da 100644
--- a/app/serializers/basic_group_serializer.rb
+++ b/app/serializers/basic_group_serializer.rb
@@ -8,5 +8,6 @@ class BasicGroupSerializer < ApplicationSerializer
              :automatic_membership_email_domains,
              :automatic_membership_retroactive,
              :primary_group,
-             :title
+             :title,
+             :grant_trust_level
 end
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index a8958b9035a..7fe190f1573 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -343,6 +343,9 @@ en:
         mods_and_admins: "Only moderators and Admins"
         members_mods_and_admins: "Only group members, moderators and admins"
         everyone: "Everyone"
+      trust_levels:
+        title: "Trust level automatically granted to members when they're added:"
+        none: "None"
 
     user_action_groups:
       "1": "Likes Given"
diff --git a/db/migrate/20150901192313_add_grant_trust_level_to_groups.rb b/db/migrate/20150901192313_add_grant_trust_level_to_groups.rb
new file mode 100644
index 00000000000..a654369a2e2
--- /dev/null
+++ b/db/migrate/20150901192313_add_grant_trust_level_to_groups.rb
@@ -0,0 +1,5 @@
+class AddGrantTrustLevelToGroups < ActiveRecord::Migration
+  def change
+    add_column :groups, :grant_trust_level, :integer
+  end
+end
diff --git a/spec/controllers/admin/groups_controller_spec.rb b/spec/controllers/admin/groups_controller_spec.rb
index b7710e7007f..75bc9ddac12 100644
--- a/spec/controllers/admin/groups_controller_spec.rb
+++ b/spec/controllers/admin/groups_controller_spec.rb
@@ -29,7 +29,8 @@ describe Admin::GroupsController do
         "automatic_membership_email_domains"=>nil,
         "automatic_membership_retroactive"=>false,
         "title"=>nil,
-        "primary_group"=>false
+        "primary_group"=>false,
+        "grant_trust_level"=>nil
       }])
     end
 
diff --git a/spec/models/group_spec.rb b/spec/models/group_spec.rb
index c1b42d643c5..b1d484d9633 100644
--- a/spec/models/group_spec.rb
+++ b/spec/models/group_spec.rb
@@ -311,4 +311,16 @@ describe Group do
     end
   end
 
+  it "correctly grants a trust level to members" do
+    group = Fabricate(:group, grant_trust_level: 2)
+    u0 = Fabricate(:user, trust_level: 0)
+    u3 = Fabricate(:user, trust_level: 3)
+
+    group.add(u0)
+    expect(u0.reload.trust_level).to eq(2)
+
+    group.add(u3)
+    expect(u3.reload.trust_level).to eq(3)
+  end
+
 end