diff --git a/django/contrib/admin/sites.py b/django/contrib/admin/sites.py
index 4b5ee57746..8209ce3b04 100644
--- a/django/contrib/admin/sites.py
+++ b/django/contrib/admin/sites.py
@@ -394,53 +394,80 @@ class AdminSite(object):
         }
         return login(request, **defaults)
 
+    def _build_app_dict(self, request, label=None):
+        """
+        Builds the app dictionary. Takes an optional label parameters to filter
+        models of a specific app.
+        """
+        app_dict = {}
+
+        if label:
+            models = {
+                m: m_a for m, m_a in self._registry.items()
+                if m._meta.app_label == label
+            }
+        else:
+            models = self._registry
+
+        for model, model_admin in models.items():
+            app_label = model._meta.app_label
+
+            has_module_perms = model_admin.has_module_permission(request)
+            if not has_module_perms:
+                if label:
+                    raise PermissionDenied
+                continue
+
+            perms = model_admin.get_model_perms(request)
+
+            # Check whether user has any perm for this module.
+            # If so, add the module to the model_list.
+            if True not in perms.values():
+                continue
+
+            info = (app_label, model._meta.model_name)
+            model_dict = {
+                'name': capfirst(model._meta.verbose_name_plural),
+                'object_name': model._meta.object_name,
+                'perms': perms,
+            }
+            if perms.get('change'):
+                try:
+                    model_dict['admin_url'] = reverse('admin:%s_%s_changelist' % info, current_app=self.name)
+                except NoReverseMatch:
+                    pass
+            if perms.get('add'):
+                try:
+                    model_dict['add_url'] = reverse('admin:%s_%s_add' % info, current_app=self.name)
+                except NoReverseMatch:
+                    pass
+
+            if app_label in app_dict:
+                app_dict[app_label]['models'].append(model_dict)
+            else:
+                app_dict[app_label] = {
+                    'name': apps.get_app_config(app_label).verbose_name,
+                    'app_label': app_label,
+                    'app_url': reverse(
+                        'admin:app_list',
+                        kwargs={'app_label': app_label},
+                        current_app=self.name,
+                    ),
+                    'has_module_perms': has_module_perms,
+                    'models': [model_dict],
+                }
+
+        if label:
+            return app_dict.get(label)
+        return app_dict
+
     @never_cache
     def index(self, request, extra_context=None):
         """
         Displays the main admin index page, which lists all of the installed
         apps that have been registered in this site.
         """
-        app_dict = {}
-        for model, model_admin in self._registry.items():
-            app_label = model._meta.app_label
-            has_module_perms = model_admin.has_module_permission(request)
-
-            if has_module_perms:
-                perms = model_admin.get_model_perms(request)
-
-                # Check whether user has any perm for this module.
-                # If so, add the module to the model_list.
-                if True in perms.values():
-                    info = (app_label, model._meta.model_name)
-                    model_dict = {
-                        'name': capfirst(model._meta.verbose_name_plural),
-                        'object_name': model._meta.object_name,
-                        'perms': perms,
-                    }
-                    if perms.get('change', False):
-                        try:
-                            model_dict['admin_url'] = reverse('admin:%s_%s_changelist' % info, current_app=self.name)
-                        except NoReverseMatch:
-                            pass
-                    if perms.get('add', False):
-                        try:
-                            model_dict['add_url'] = reverse('admin:%s_%s_add' % info, current_app=self.name)
-                        except NoReverseMatch:
-                            pass
-                    if app_label in app_dict:
-                        app_dict[app_label]['models'].append(model_dict)
-                    else:
-                        app_dict[app_label] = {
-                            'name': apps.get_app_config(app_label).verbose_name,
-                            'app_label': app_label,
-                            'app_url': reverse(
-                                'admin:app_list',
-                                kwargs={'app_label': app_label},
-                                current_app=self.name,
-                            ),
-                            'has_module_perms': has_module_perms,
-                            'models': [model_dict],
-                        }
+        app_dict = self._build_app_dict(request)
 
         # Sort the apps alphabetically.
         app_list = list(six.itervalues(app_dict))
@@ -463,52 +490,12 @@ class AdminSite(object):
                                 'admin/index.html', context)
 
     def app_index(self, request, app_label, extra_context=None):
-        app_name = apps.get_app_config(app_label).verbose_name
-        app_dict = {}
-        for model, model_admin in self._registry.items():
-            if app_label == model._meta.app_label:
-                has_module_perms = model_admin.has_module_permission(request)
-                if not has_module_perms:
-                    raise PermissionDenied
-
-                perms = model_admin.get_model_perms(request)
-
-                # Check whether user has any perm for this module.
-                # If so, add the module to the model_list.
-                if True in perms.values():
-                    info = (app_label, model._meta.model_name)
-                    model_dict = {
-                        'name': capfirst(model._meta.verbose_name_plural),
-                        'object_name': model._meta.object_name,
-                        'perms': perms,
-                    }
-                    if perms.get('change'):
-                        try:
-                            model_dict['admin_url'] = reverse('admin:%s_%s_changelist' % info, current_app=self.name)
-                        except NoReverseMatch:
-                            pass
-                    if perms.get('add'):
-                        try:
-                            model_dict['add_url'] = reverse('admin:%s_%s_add' % info, current_app=self.name)
-                        except NoReverseMatch:
-                            pass
-                    if app_dict:
-                        app_dict['models'].append(model_dict),
-                    else:
-                        # First time around, now that we know there's
-                        # something to display, add in the necessary meta
-                        # information.
-                        app_dict = {
-                            'name': app_name,
-                            'app_label': app_label,
-                            'app_url': '',
-                            'has_module_perms': has_module_perms,
-                            'models': [model_dict],
-                        }
+        app_dict = self._build_app_dict(request, app_label)
         if not app_dict:
             raise Http404('The requested admin page does not exist.')
         # Sort the models alphabetically within each app.
         app_dict['models'].sort(key=lambda x: x['name'])
+        app_name = apps.get_app_config(app_label).verbose_name
         context = dict(self.each_context(request),
             title=_('%(app)s administration') % {'app': app_name},
             app_list=[app_dict],