diff --git a/app/assets/javascripts/discourse/components/tag-chooser.js.es6 b/app/assets/javascripts/discourse/components/tag-chooser.js.es6
index d3daddf44b4..d9b3863cf58 100644
--- a/app/assets/javascripts/discourse/components/tag-chooser.js.es6
+++ b/app/assets/javascripts/discourse/components/tag-chooser.js.es6
@@ -8,7 +8,7 @@ export default Ember.TextField.extend({
   classNameBindings: [':tag-chooser'],
   attributeBindings: ['tabIndex', 'placeholderKey', 'categoryId'],
 
-  _setupTags: function() {
+  _initValue: function() {
     const tags = this.get('tags') || [];
     this.set('value', tags.join(", "));
   }.on('init'),
@@ -79,7 +79,7 @@ export default Ember.TextField.extend({
         list.push(item);
       },
       formatSelection: function (data) {
-          return data ? renderTag(this.text(data)) : undefined;
+        return data ? renderTag(this.text(data)) : undefined;
       },
       formatSelectionCssClass: function(){
         return "discourse-tag-select2";
diff --git a/app/assets/javascripts/discourse/components/tag-group-chooser.js.es6 b/app/assets/javascripts/discourse/components/tag-group-chooser.js.es6
new file mode 100644
index 00000000000..ae9498af2b5
--- /dev/null
+++ b/app/assets/javascripts/discourse/components/tag-group-chooser.js.es6
@@ -0,0 +1,84 @@
+function renderTagGroup(tag) {
+  return "<a class='discourse-tag'>" + Handlebars.Utils.escapeExpression(tag.text ? tag.text : tag) + "</a>";
+};
+
+export default Ember.TextField.extend({
+  classNameBindings: [':tag-chooser'],
+  attributeBindings: ['tabIndex', 'placeholderKey', 'categoryId'],
+
+  _initValue: function() {
+    const names = this.get('tagGroups') || [];
+    this.set('value', names.join(", "));
+  }.on('init'),
+
+  _valueChanged: function() {
+    const names = this.get('value').split(',').map(v => v.trim()).reject(v => v.length === 0).uniq();
+    this.set('tagGroups', names);
+  }.observes('value'),
+
+  _tagGroupsChanged: function() {
+    const $chooser = this.$(),
+          val = this.get('value');
+
+    if ($chooser && val !== this.get('tagGroups')) {
+      if (this.get('tagGroups')) {
+        const data = this.get('tagGroups').map((t) => {return {id: t, text: t};});
+        $chooser.select2('data', data);
+      } else {
+        $chooser.select2('data', []);
+      }
+    }
+  }.observes('tagGroups'),
+
+  _initializeChooser: function() {
+    const self = this;
+
+    this.$().select2({
+      tags: true,
+      placeholder: this.get('placeholderKey') ? I18n.t(this.get('placeholderKey')) : null,
+      initSelection(element, callback) {
+        const data = [];
+
+        function splitVal(string, separator) {
+          var val, i, l;
+          if (string === null || string.length < 1) return [];
+          val = string.split(separator);
+          for (i = 0, l = val.length; i < l; i = i + 1) val[i] = $.trim(val[i]);
+          return val;
+        }
+
+        $(splitVal(element.val(), ",")).each(function () {
+          data.push({ id: this, text: this });
+        });
+
+        callback(data);
+      },
+      formatSelection: function (data) {
+        return data ? renderTagGroup(this.text(data)) : undefined;
+      },
+      formatSelectionCssClass: function(){
+        return "discourse-tag-select2";
+      },
+      formatResult: renderTagGroup,
+      multiple: true,
+      ajax: {
+        quietMillis: 200,
+        cache: true,
+        url: Discourse.getURL("/tag_groups/filter/search"),
+        dataType: 'json',
+        data: function (term) {
+          return { q: term, limit: self.siteSettings.max_tag_search_results };
+        },
+        results: function (data) {
+          data.results = data.results.sort(function(a,b) { return a.text > b.text; });
+          return data;
+        }
+      },
+    });
+  }.on('didInsertElement'),
+
+  _destroyChooser: function() {
+    this.$().select2('destroy');
+  }.on('willDestroyElement')
+
+});
diff --git a/app/assets/javascripts/discourse/models/category.js.es6 b/app/assets/javascripts/discourse/models/category.js.es6
index 0e013cf8337..8d1eb8ba879 100644
--- a/app/assets/javascripts/discourse/models/category.js.es6
+++ b/app/assets/javascripts/discourse/models/category.js.es6
@@ -87,7 +87,8 @@ const Category = RestModel.extend({
         custom_fields: this.get('custom_fields'),
         topic_template: this.get('topic_template'),
         suppress_from_homepage: this.get('suppress_from_homepage'),
-        allowed_tags: this.get('allowed_tags')
+        allowed_tags: this.get('allowed_tags'),
+        allowed_tag_groups: this.get('allowed_tag_groups')
       },
       type: this.get('id') ? 'PUT' : 'POST'
     });
diff --git a/app/assets/javascripts/discourse/templates/components/edit-category-tags.hbs b/app/assets/javascripts/discourse/templates/components/edit-category-tags.hbs
index 632690bedc2..abd70f23074 100644
--- a/app/assets/javascripts/discourse/templates/components/edit-category-tags.hbs
+++ b/app/assets/javascripts/discourse/templates/components/edit-category-tags.hbs
@@ -1,4 +1,7 @@
 <section class="field">
   <p>{{i18n 'category.tags_allowed_tags'}}</p>
   {{tag-chooser placeholderKey="category.tags_placeholder" tags=category.allowed_tags}}
+
+  <p>{{i18n 'category.tags_allowed_tag_groups'}}</p>
+  {{tag-group-chooser placeholderKey="category.tag_groups_placeholder" tagGroups=category.allowed_tag_groups}}
 </section>
diff --git a/app/controllers/categories_controller.rb b/app/controllers/categories_controller.rb
index 954cd3efcb3..8617970c820 100644
--- a/app/controllers/categories_controller.rb
+++ b/app/controllers/categories_controller.rb
@@ -180,7 +180,10 @@ class CategoriesController < ApplicationController
           end
         end
 
-        params[:allowed_tags] ||= [] if SiteSetting.tagging_enabled
+        if SiteSetting.tagging_enabled
+          params[:allowed_tags] ||= []
+          params[:allowed_tag_groups] ||= []
+        end
 
         params.permit(*required_param_keys,
                         :position,
@@ -197,7 +200,8 @@ class CategoriesController < ApplicationController
                         :topic_template,
                         :custom_fields => [params[:custom_fields].try(:keys)],
                         :permissions => [*p.try(:keys)],
-                        :allowed_tags => [])
+                        :allowed_tags => [],
+                        :allowed_tag_groups => [])
       end
     end
 
diff --git a/app/controllers/tag_groups_controller.rb b/app/controllers/tag_groups_controller.rb
index 9ba20c9da9c..4bfc943a160 100644
--- a/app/controllers/tag_groups_controller.rb
+++ b/app/controllers/tag_groups_controller.rb
@@ -49,6 +49,19 @@ class TagGroupsController < ApplicationController
     render json: success_json
   end
 
+  def search
+    matches = if params[:q].present?
+      term = params[:q].strip.downcase
+      TagGroup.where('lower(name) like ?', "%#{term}%")
+    else
+      TagGroup.all
+    end
+
+    matches = matches.order('name').limit(params[:limit] || 5)
+
+    render json: { results: matches.map { |x| { id: x.name, text: x.name } } }
+  end
+
   private
 
     def fetch_tag_group
diff --git a/app/models/category.rb b/app/models/category.rb
index 97341b9a48b..92f0b751723 100644
--- a/app/models/category.rb
+++ b/app/models/category.rb
@@ -55,8 +55,10 @@ class Category < ActiveRecord::Base
   belongs_to :parent_category, class_name: 'Category'
   has_many :subcategories, class_name: 'Category', foreign_key: 'parent_category_id'
 
-  has_many :category_tags
+  has_many :category_tags, dependent: :destroy
   has_many :tags, through: :category_tags
+  has_many :category_tag_groups, dependent: :destroy
+  has_many :tag_groups, through: :category_tag_groups
 
   scope :latest, ->{ order('topic_count desc') }
 
@@ -319,6 +321,10 @@ SQL
     DiscourseTagging.add_or_create_tags_by_name(self, tag_names_arg)
   end
 
+  def allowed_tag_groups=(group_names)
+    self.tag_groups = TagGroup.where(name: group_names).all.to_a
+  end
+
   def downcase_email
     self.email_in = (email_in || "").strip.downcase.presence
   end
diff --git a/app/models/category_tag_group.rb b/app/models/category_tag_group.rb
new file mode 100644
index 00000000000..b73c6788ddd
--- /dev/null
+++ b/app/models/category_tag_group.rb
@@ -0,0 +1,4 @@
+class CategoryTagGroup < ActiveRecord::Base
+  belongs_to :category
+  belongs_to :tag_group
+end
diff --git a/app/models/tag_group.rb b/app/models/tag_group.rb
index 9bd7f11bb2b..dea1199a62a 100644
--- a/app/models/tag_group.rb
+++ b/app/models/tag_group.rb
@@ -1,6 +1,10 @@
 class TagGroup < ActiveRecord::Base
+  validates_uniqueness_of :name, case_sensitive: false
+
   has_many :tag_group_memberships, dependent: :destroy
   has_many :tags, through: :tag_group_memberships
+  has_many :category_tag_groups, dependent: :destroy
+  has_many :categories, through: :category_tag_groups
 
   def tag_names=(tag_names_arg)
     DiscourseTagging.add_or_create_tags_by_name(self, tag_names_arg)
diff --git a/app/serializers/category_serializer.rb b/app/serializers/category_serializer.rb
index bf83663d485..bb9758cad16 100644
--- a/app/serializers/category_serializer.rb
+++ b/app/serializers/category_serializer.rb
@@ -14,7 +14,8 @@ class CategorySerializer < BasicCategorySerializer
              :is_special,
              :allow_badges,
              :custom_fields,
-             :allowed_tags
+             :allowed_tags,
+             :allowed_tag_groups
 
   def group_permissions
     @group_permissions ||= begin
@@ -86,4 +87,12 @@ class CategorySerializer < BasicCategorySerializer
     object.tags.pluck(:name)
   end
 
+  def include_allowed_tag_groups?
+    SiteSetting.tagging_enabled
+  end
+
+  def allowed_tag_groups
+    object.tag_groups.pluck(:name)
+  end
+
 end
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index 4ee08c4f332..3c3a4f6ddd7 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -1732,7 +1732,9 @@ en:
       topic_template: "Topic Template"
       tags: "Tags"
       tags_allowed_tags: "Tags that can only be used in this category:"
+      tags_allowed_tag_groups: "Tag groups that can only be used in this category:"
       tags_placeholder: "(Optional) list of allowed tags"
+      tag_groups_placeholder: "(Optional) list of allowed tag groups"
       delete: 'Delete Category'
       create: 'New Category'
       create_long: 'Create a new category'
diff --git a/config/routes.rb b/config/routes.rb
index ff509dbf720..f7839f043b1 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -636,7 +636,12 @@ Discourse::Application.routes.draw do
       end
     end
   end
-  resources :tag_groups, except: [:new, :edit]
+
+  resources :tag_groups, except: [:new, :edit] do
+    collection do
+      get '/filter/search' => 'tag_groups#search'
+    end
+  end
 
   Discourse.filters.each do |filter|
     root to: "list##{filter}", constraints: HomePageConstraint.new("#{filter}"), :as => "list_#{filter}"
diff --git a/db/migrate/20160606204319_create_category_tag_groups.rb b/db/migrate/20160606204319_create_category_tag_groups.rb
new file mode 100644
index 00000000000..628f131ddc2
--- /dev/null
+++ b/db/migrate/20160606204319_create_category_tag_groups.rb
@@ -0,0 +1,11 @@
+class CreateCategoryTagGroups < ActiveRecord::Migration
+  def change
+    create_table :category_tag_groups do |t|
+      t.references :category,  null: false
+      t.references :tag_group, null: false
+      t.timestamps
+    end
+
+    add_index :category_tag_groups, [:category_id, :tag_group_id], name: "idx_category_tag_groups_ix1", unique: true
+  end
+end
diff --git a/lib/discourse_tagging.rb b/lib/discourse_tagging.rb
index 48ce1c00dc8..72ef4aecd11 100644
--- a/lib/discourse_tagging.rb
+++ b/lib/discourse_tagging.rb
@@ -72,10 +72,33 @@ module DiscourseTagging
         query = query.where('tags.name NOT IN (?)', staff_tag_names) if staff_tag_names.present?
       end
 
-      if opts[:category] && opts[:category].tags.count > 0
-        query = query.where("tags.id IN (SELECT tag_id FROM category_tags WHERE category_id = ?)", opts[:category].id)
-      elsif CategoryTag.exists?
-        query = query.where("tags.id NOT IN (SELECT tag_id FROM category_tags)")
+      # Filters for category-specific tags:
+
+      if opts[:category] && (opts[:category].tags.count > 0 || opts[:category].tag_groups.count > 0)
+        if opts[:category].tags.count > 0 && opts[:category].tag_groups.count > 0
+          tag_group_ids = opts[:category].tag_groups.pluck(:id)
+          query = query.where(
+            "tags.id IN (SELECT tag_id FROM category_tags WHERE category_id = ?
+              UNION
+              SELECT tag_id FROM tag_group_memberships WHERE tag_group_id = ?)",
+            opts[:category].id, tag_group_ids
+          )
+        elsif opts[:category].tags.count > 0
+          query = query.where("tags.id IN (SELECT tag_id FROM category_tags WHERE category_id = ?)", opts[:category].id)
+        else # opts[:category].tag_groups.count > 0
+          tag_group_ids = opts[:category].tag_groups.pluck(:id)
+          query = query.where("tags.id IN (SELECT tag_id FROM tag_group_memberships WHERE tag_group_id = ?)", tag_group_ids)
+        end
+      else
+        # exclude tags that are restricted to other categories
+        if CategoryTag.exists?
+          query = query.where("tags.id NOT IN (SELECT tag_id FROM category_tags)")
+        end
+
+        if CategoryTagGroup.exists?
+          tag_group_ids = CategoryTagGroup.pluck(:tag_group_id).uniq
+          query = query.where("tags.id NOT IN (SELECT tag_id FROM tag_group_memberships WHERE tag_group_id = ?)", tag_group_ids)
+        end
       end
     end
 
diff --git a/spec/fabricators/tag_group_fabricator.rb b/spec/fabricators/tag_group_fabricator.rb
new file mode 100644
index 00000000000..f410aa5bd75
--- /dev/null
+++ b/spec/fabricators/tag_group_fabricator.rb
@@ -0,0 +1,3 @@
+Fabricator(:tag_group) do
+  name { sequence(:name) { |i| "tag_group_#{i}" } }
+end
diff --git a/spec/integration/category_tag_spec.rb b/spec/integration/category_tag_spec.rb
index 358db1e0551..9b2f0c3a90d 100644
--- a/spec/integration/category_tag_spec.rb
+++ b/spec/integration/category_tag_spec.rb
@@ -4,6 +4,11 @@ require 'rails_helper'
 require_dependency 'post_creator'
 
 describe "category tag restrictions" do
+
+  def sorted_tag_names(tag_records)
+    tag_records.map(&:name).sort
+  end
+
   let!(:tag1) { Fabricate(:tag) }
   let!(:tag2) { Fabricate(:tag) }
   let!(:tag3) { Fabricate(:tag) }
@@ -57,4 +62,37 @@ describe "category tag restrictions" do
       expect { other_category.update(allowed_tags: [tag1.name, 'tag-stuff', tag2.name, 'another-tag']) }.to change { Tag.count }.by(2)
     end
   end
+
+  context "tag groups restricted to a category" do
+    let!(:tag_group1)     { Fabricate(:tag_group) }
+    let(:category)        { Fabricate(:category) }
+    let(:other_category)  { Fabricate(:category) }
+
+    before do
+      tag_group1.tags = [tag1, tag2]
+    end
+
+    it "tags in the group are used by category tag restrictions" do
+      category.allowed_tag_groups = [tag_group1.name]
+      category.reload
+
+      expect(sorted_tag_names(DiscourseTagging.filter_allowed_tags(Tag.all, Guardian.new(user), {for_input: true, category: category}))).to eq(sorted_tag_names([tag1, tag2]))
+      expect(sorted_tag_names(DiscourseTagging.filter_allowed_tags(Tag.all, Guardian.new(user), {for_input: true}))).to eq(sorted_tag_names([tag3, tag4]))
+
+      tag_group1.tags = [tag2, tag3, tag4]
+      expect(sorted_tag_names(DiscourseTagging.filter_allowed_tags(Tag.all, Guardian.new(user), {for_input: true, category: category}))).to eq(sorted_tag_names([tag2, tag3, tag4]))
+      expect(sorted_tag_names(DiscourseTagging.filter_allowed_tags(Tag.all, Guardian.new(user), {for_input: true}))).to eq(sorted_tag_names([tag1]))
+      expect(sorted_tag_names(DiscourseTagging.filter_allowed_tags(Tag.all, Guardian.new(user), {for_input: true, category: other_category}))).to eq(sorted_tag_names([tag1]))
+    end
+
+    it "groups and individual tags can be mixed" do
+      category.allowed_tag_groups = [tag_group1.name]
+      category.allowed_tags = [tag4.name]
+      category.reload
+
+      expect(sorted_tag_names(DiscourseTagging.filter_allowed_tags(Tag.all, Guardian.new(user), {for_input: true, category: category}))).to eq(sorted_tag_names([tag1, tag2, tag4]))
+      expect(sorted_tag_names(DiscourseTagging.filter_allowed_tags(Tag.all, Guardian.new(user), {for_input: true}))).to eq(sorted_tag_names([tag3]))
+      expect(sorted_tag_names(DiscourseTagging.filter_allowed_tags(Tag.all, Guardian.new(user), {for_input: true, category: other_category}))).to eq(sorted_tag_names([tag3]))
+    end
+  end
 end