diff --git a/src/app.py b/src/app.py
index 82d7119d..08145748 100644
--- a/src/app.py
+++ b/src/app.py
@@ -3342,7 +3342,7 @@ def get_prov_info():
                 distinct_organ_uuid_list.append(item['uuid'])
 
                 organ_code = item['organ'].upper()
-                validate_organ_code(organ_code, organ_types_dict)
+                validate_organ_code(organ_code)
 
                 distinct_organ_type_list.append(organ_types_dict[organ_code].lower())
             internal_dict[HEADER_ORGAN_HUBMAP_ID] = distinct_organ_hubmap_id_list
@@ -3662,7 +3662,7 @@ def get_prov_info_for_dataset(id):
             distinct_organ_uuid_list.append(item['uuid'])
 
             organ_code = item['organ'].upper()
-            validate_organ_code(organ_code, organ_types_dict )
+            validate_organ_code(organ_code)
 
             distinct_organ_type_list.append(organ_types_dict[organ_code].lower())
         internal_dict[HEADER_ORGAN_HUBMAP_ID] = distinct_organ_hubmap_id_list
@@ -3858,7 +3858,7 @@ def sankey_data():
             internal_dict[HEADER_DATASET_GROUP_NAME] = dataset[HEADER_DATASET_GROUP_NAME]
 
             organ_code = dataset[HEADER_ORGAN_TYPE].upper()
-            validate_organ_code(organ_code, organ_types_dict)
+            validate_organ_code(organ_code)
 
             internal_dict[HEADER_ORGAN_TYPE] = organ_types_dict[organ_code].lower()
 
@@ -5554,9 +5554,8 @@ def access_level_prefix_dir(dir_name):
 ----------
 organ_code : str
 """
-def validate_organ_code(organ_code, organ_types_dict=None):
-    if organ_types_dict is None:
-        organ_types_dict = schema_manager.get_organ_types()
+def validate_organ_code(organ_code):
+    organ_types_dict = schema_manager.get_organ_types()
     if not organ_code.isalpha() or not len(organ_code) == 2:
         internal_server_error(f"Invalid organ code {organ_code}. Must be 2-letter alphabetic code")
 
diff --git a/src/schema/schema_manager.py b/src/schema/schema_manager.py
index 4012465f..ff93c0b2 100644
--- a/src/schema/schema_manager.py
+++ b/src/schema/schema_manager.py
@@ -39,6 +39,7 @@
 _neo4j_driver = None
 _memcached_client = None
 _memcached_prefix = None
+_organ_types = None
 
 
 ####################################################################################################
@@ -2160,29 +2161,34 @@ def delete_memcached_cache(uuids_list):
 """
 def get_organ_types():
     global _ontology_api_url
+    global _organ_types
 
-    target_url = _ontology_api_url + SchemaConstants.ONTOLOGY_API_ORGAN_TYPES_ENDPOINT
+    if _organ_types is None:
+        target_url = _ontology_api_url + SchemaConstants.ONTOLOGY_API_ORGAN_TYPES_ENDPOINT
 
-    # Use Memcached to improve performance
-    response = make_request_get(target_url, internal_token_used = True)
+        # Use Memcached to improve performance
+        response = make_request_get(target_url, internal_token_used = True)
 
-    # Invoke .raise_for_status(), an HTTPError will be raised with certain status codes
-    response.raise_for_status()
+        # Invoke .raise_for_status(), an HTTPError will be raised with certain status codes
+        response.raise_for_status()
 
-    if response.status_code == 200:
-        return response.json()
-    else:
-        # Log the full stack trace, prepend a line with our message
-        logger.exception("Unable to make a request to query the organ types via ontology-api")
+        if response.status_code == 200:
+            _organ_types = response.json()
+            return _organ_types
+        else:
+            # Log the full stack trace, prepend a line with our message
+            logger.exception("Unable to make a request to query the organ types via ontology-api")
 
-        logger.debug("======get_organ_types() status code from ontology-api======")
-        logger.debug(response.status_code)
+            logger.debug("======get_organ_types() status code from ontology-api======")
+            logger.debug(response.status_code)
 
-        logger.debug("======get_organ_types() response text from ontology-api======")
-        logger.debug(response.text)
+            logger.debug("======get_organ_types() response text from ontology-api======")
+            logger.debug(response.text)
 
-        # Also bubble up the error message from ontology-api
-        raise requests.exceptions.RequestException(response.text)
+            # Also bubble up the error message from ontology-api
+            raise requests.exceptions.RequestException(response.text)
+    else:
+        return _organ_types
 
 
 """