diff --git a/core/code_systems/serializers.py b/core/code_systems/serializers.py
index 54a76ea4..63f9cc58 100644
--- a/core/code_systems/serializers.py
+++ b/core/code_systems/serializers.py
@@ -280,7 +280,7 @@ def to_representation(self, instance):
 
     def create(self, validated_data):
         concepts = validated_data.pop('concepts', [])
-        uri = self.context['request'].path + validated_data['mnemonic']
+        uri = '/'.join([self.context['request'].path.rstrip('/'), validated_data['mnemonic']])
         ident = IdentifierSerializer.include_ocl_identifier(uri, RESOURCE_TYPE, validated_data)
         source = SourceCreateOrUpdateSerializer().prepare_object(validated_data)
 
diff --git a/core/code_systems/tests.py b/core/code_systems/tests.py
index f8f2f91a..17f6a174 100644
--- a/core/code_systems/tests.py
+++ b/core/code_systems/tests.py
@@ -345,7 +345,7 @@ def test_put_code_system_without_concepts(self):
     @patch('core.sources.models.index_source_mappings', Mock(__name__='index_source_mappings'))
     def test_post_code_system_with_concepts(self):
         response = self.client.post(
-            f'/users/{self.user.mnemonic}/CodeSystem/',
+            f'/users/{self.user.mnemonic}/CodeSystem',
             HTTP_AUTHORIZATION='Token ' + self.user_token,
             data={
                 'url': 'http://localhost/url',
diff --git a/core/code_systems/urls.py b/core/code_systems/urls.py
index d9a10f2d..b290d6b2 100644
--- a/core/code_systems/urls.py
+++ b/core/code_systems/urls.py
@@ -5,6 +5,9 @@
 urlpatterns = [
     path('', views.CodeSystemListView.as_view(), name='code-system-list'),
     path('$lookup/', views.CodeSystemListLookupView.as_view(), name='code-system-list-lookup'),
+    path('$lookup', views.CodeSystemListLookupView.as_view(), name='code-system-list-lookup_no_slash'),
     path('$validate-code/', views.CodeSystemValidateCodeView.as_view(), name='code-system-validate-code'),
-    path("<str:source>/", views.CodeSystemRetrieveUpdateView.as_view(), name='code-system-detail')
+    path('$validate-code', views.CodeSystemValidateCodeView.as_view(), name='code-system-validate-code_no_slash'),
+    path("<str:source>/", views.CodeSystemRetrieveUpdateView.as_view(), name='code-system-detail'),
+    path("<str:source>", views.CodeSystemRetrieveUpdateView.as_view(), name='code-system-detail_no_slash'),
 ]
diff --git a/core/code_systems/views.py b/core/code_systems/views.py
index 5c24d550..a03bd3ab 100644
--- a/core/code_systems/views.py
+++ b/core/code_systems/views.py
@@ -77,6 +77,9 @@ class CodeSystemListLookupView(ConceptRetrieveUpdateDestroyView):
     def is_container_version_specified(self):
         return True
 
+    def verify_scope(self):
+        pass
+
     def get_queryset(self):
         queryset = super().get_queryset()
         code = self.request.query_params.get('code')
diff --git a/core/concept_maps/serializers.py b/core/concept_maps/serializers.py
index 3a9b591a..c7105bb2 100644
--- a/core/concept_maps/serializers.py
+++ b/core/concept_maps/serializers.py
@@ -156,7 +156,7 @@ def to_representation(self, instance):
 
     def create(self, validated_data):
         mappings = validated_data.pop('mappings', [])
-        uri = self.context['request'].path + validated_data['mnemonic']
+        uri = '/'.join([self.context['request'].path.rstrip('/'), validated_data['mnemonic']])
         ident = IdentifierSerializer.include_ocl_identifier(uri, RESOURCE_TYPE, validated_data)
         source = SourceCreateOrUpdateSerializer().prepare_object(validated_data)
 
diff --git a/core/concept_maps/urls.py b/core/concept_maps/urls.py
index 0ebfdab5..e3085973 100644
--- a/core/concept_maps/urls.py
+++ b/core/concept_maps/urls.py
@@ -4,6 +4,8 @@
 
 urlpatterns = [
     path('', views.ConceptMapListView.as_view(), name='concept-map-list'),
-    path('$translate', views.ConceptMapTranslateView.as_view(), name='concept-map-list-translate'),
-    path("<str:source>/", views.ConceptMapRetrieveUpdateView.as_view(), name='concept-map-detail')
+    path('$translate/', views.ConceptMapTranslateView.as_view(), name='concept-map-list-translate'),
+    path('$translate', views.ConceptMapTranslateView.as_view(), name='concept-map-list-translate_no_slash'),
+    path("<str:source>/", views.ConceptMapRetrieveUpdateView.as_view(), name='concept-map-detail'),
+    path("<str:source>", views.ConceptMapRetrieveUpdateView.as_view(), name='concept-map-detail_no_slash')
 ]
diff --git a/core/orgs/urls.py b/core/orgs/urls.py
index d93ea39d..b023f3bb 100644
--- a/core/orgs/urls.py
+++ b/core/orgs/urls.py
@@ -22,8 +22,11 @@
     path('<str:org>/repos/', include('core.repos.urls'), name='org-repos-urls'),
     path('<str:org>/sources/', include('core.sources.urls')),
     path('<str:org>/CodeSystem/', include('core.code_systems.urls'), name='code_systems_urls'),
+    path('<str:org>/CodeSystem', include('core.code_systems.urls'), name='code_systems_urls_no_slash'),
     path('<str:org>/ValueSet/', include('core.value_sets.urls'), name='value_sets_urls'),
+    path('<str:org>/ValueSet', include('core.value_sets.urls'), name='value_sets_urls_no_slash'),
     path('<str:org>/ConceptMap/', include('core.concept_maps.urls'), name='concept_maps_urls'),
+    path('<str:org>/ConceptMap', include('core.concept_maps.urls'), name='concept_maps_urls_no_slash'),
     path('<str:org>/collections/', include('core.collections.urls')),
     path('<str:org>/pins/', include('core.pins.urls')),
     path('<str:org>/events/', include('core.events.urls')),
diff --git a/core/urls.py b/core/urls.py
index a8474e61..2086c15f 100644
--- a/core/urls.py
+++ b/core/urls.py
@@ -72,8 +72,11 @@
     # TODO: require FHIR subdomain
     path('fhir/', include('core.fhir.urls'), name='fhir_urls'),
     path('fhir/CodeSystem/', include('core.code_systems.urls'), name='code_systems_urls'),
+    path('fhir/CodeSystem', include('core.code_systems.urls'), name='code_systems_urls_no_slash'),
     path('fhir/ValueSet/', include('core.value_sets.urls'), name='value_sets_urls'),
+    path('fhir/ValueSet', include('core.value_sets.urls'), name='value_sets_urls_no_slash'),
     path('fhir/ConceptMap/', include('core.concept_maps.urls'), name='concept_maps_urls'),
+    path('fhir/ConceptMap', include('core.concept_maps.urls'), name='concept_maps_urls_no_slash'),
 
     path('collections/', include('core.collections.urls'), name='collections_urls'),
     path('concepts/', concept_views.ConceptListView.as_view(), name='all_concepts_urls'),
diff --git a/core/users/urls.py b/core/users/urls.py
index 7ebd5fa9..34dc1bce 100644
--- a/core/users/urls.py
+++ b/core/users/urls.py
@@ -48,6 +48,9 @@
 
     # TODO: require FHIR subdomain
     path('<str:user>/CodeSystem/', include('core.code_systems.urls'), name='code_systems_urls'),
+    path('<str:user>/CodeSystem', include('core.code_systems.urls'), name='code_systems_urls_no_slash'),
     path('<str:user>/ValueSet/', include('core.value_sets.urls'), name='value_sets_urls'),
+    path('<str:user>/ValueSet', include('core.value_sets.urls'), name='value_sets_urls_no_slash'),
     path('<str:user>/ConceptMap/', include('core.concept_maps.urls'), name='concept_maps_urls'),
+    path('<str:user>/ConceptMap', include('core.concept_maps.urls'), name='concept_maps_urls_no_slash'),
 ]
diff --git a/core/value_sets/serializers.py b/core/value_sets/serializers.py
index b9ce05d0..383aaf4c 100644
--- a/core/value_sets/serializers.py
+++ b/core/value_sets/serializers.py
@@ -165,7 +165,7 @@ class Meta:
                   'immutable', 'text', 'compose')
 
     def create(self, validated_data):
-        uri = self.context['request'].path + validated_data['mnemonic']
+        uri = '/'.join([self.context['request'].path.rstrip('/'), validated_data['mnemonic']])
         ident = IdentifierSerializer.include_ocl_identifier(uri, RESOURCE_TYPE, validated_data)
         collection = CollectionCreateOrUpdateSerializer().prepare_object(validated_data)
         collection_version = collection.version if collection.version != HEAD else '0.1'
diff --git a/core/value_sets/urls.py b/core/value_sets/urls.py
index 424a457a..f642c0ed 100644
--- a/core/value_sets/urls.py
+++ b/core/value_sets/urls.py
@@ -5,7 +5,12 @@
 urlpatterns = [
     path('', views.ValueSetListView.as_view(), name='value-set-list'),
     path("<str:collection>/$validate-code/", views.ValueSetValidateCodeView.as_view(), name='value-set-validate-code'),
+    path("<str:collection>/$validate-code", views.ValueSetValidateCodeView.as_view(),
+         name='value-set-validate-code_no_slash'),
     path("$validate-code/", views.ValueSetValidateCodeView.as_view(), name='value-set-validate-code-global'),
-    path("<str:collection>/$expand/", views.ValueSetExpandView.as_view(), name='value-set-validate-code'),
+    path("$validate-code", views.ValueSetValidateCodeView.as_view(), name='value-set-validate-code-global_no_slash'),
+    path("<str:collection>/$expand/", views.ValueSetExpandView.as_view(), name='value-set-expand'),
+    path("<str:collection>/$expand", views.ValueSetExpandView.as_view(), name='value-set-expand_no_slash'),
     path("<str:collection>/", views.ValueSetRetrieveUpdateView.as_view(), name='value-set-detail'),
+    path("<str:collection>", views.ValueSetRetrieveUpdateView.as_view(), name='value-set-detail_no_slash'),
 ]