diff --git a/CRM/Contact/BAO/ContactType.php b/CRM/Contact/BAO/ContactType.php
index 8ee3011f2779..b2316c4d40e6 100644
--- a/CRM/Contact/BAO/ContactType.php
+++ b/CRM/Contact/BAO/ContactType.php
@@ -155,59 +155,39 @@ public static function basicTypePairs($all = FALSE, $key = 'name') {
    *   Array of sub type information
    */
   public static function subTypeInfo($contactType = NULL, $all = FALSE, $ignoreCache = FALSE, $reset = FALSE) {
-    static $_cache = NULL;
-
-    if ($reset === TRUE) {
-      $_cache = NULL;
-    }
-
-    if ($_cache === NULL) {
-      $_cache = [];
-    }
-    if ($contactType && !is_array($contactType)) {
-      $contactType = [$contactType];
-    }
-
     $argString = $all ? 'CRM_CT_STI_1_' : 'CRM_CT_STI_0_';
     if (!empty($contactType)) {
-      $argString .= implode('_', $contactType);
+      $argString .= implode('_', (array) $contactType);
     }
+    if (!Civi::cache('contactSubTypes')->has($argString) || $ignoreCache || $reset) {
+      $ctWHERE = '';
+      if (!empty($contactType)) {
+        $ctWHERE = " AND parent.name IN ('" . implode("','", $contactType) . "')";
+      }
 
-    if ((!array_key_exists($argString, $_cache)) || $ignoreCache) {
-      $cache = CRM_Utils_Cache::singleton();
-      $_cache[$argString] = $cache->get($argString);
-      if (!$_cache[$argString] || $ignoreCache) {
-        $_cache[$argString] = [];
-
-        $ctWHERE = '';
-        if (!empty($contactType)) {
-          $ctWHERE = " AND parent.name IN ('" . implode("','", $contactType) . "')";
-        }
-
-        $sql = "
+      $sql = "
 SELECT subtype.*, parent.name as parent, parent.label as parent_label
 FROM   civicrm_contact_type subtype
 INNER JOIN civicrm_contact_type parent ON subtype.parent_id = parent.id
 WHERE  subtype.name IS NOT NULL AND subtype.parent_id IS NOT NULL {$ctWHERE}
 ";
-        if ($all === FALSE) {
-          $sql .= " AND subtype.is_active = 1 AND parent.is_active = 1 ORDER BY parent.id";
-        }
-        $dao = CRM_Core_DAO::executeQuery($sql, [],
-          FALSE, 'CRM_Contact_DAO_ContactType'
-        );
-        while ($dao->fetch()) {
-          $value = [];
-          CRM_Core_DAO::storeValues($dao, $value);
-          $value['parent'] = $dao->parent;
-          $value['parent_label'] = $dao->parent_label;
-          $_cache[$argString][$dao->name] = $value;
-        }
-
-        $cache->set($argString, $_cache[$argString]);
+      if ($all === FALSE) {
+        $sql .= " AND subtype.is_active = 1 AND parent.is_active = 1 ORDER BY parent.id";
       }
+      $dao = CRM_Core_DAO::executeQuery($sql, [],
+        FALSE, 'CRM_Contact_DAO_ContactType'
+      );
+      $values = [];
+      while ($dao->fetch()) {
+        $value = [];
+        CRM_Core_DAO::storeValues($dao, $value);
+        $value['parent'] = $dao->parent;
+        $value['parent_label'] = $dao->parent_label;
+        $values[$dao->name] = $value;
+      }
+      Civi::cache('contactSubTypes')->set($argString, $values);
     }
-    return $_cache[$argString];
+    return Civi::cache('contactSubTypes')->get($argString);
   }
 
   /**
diff --git a/CRM/Utils/System.php b/CRM/Utils/System.php
index 622e1aae9acc..40675d4f79ac 100644
--- a/CRM/Utils/System.php
+++ b/CRM/Utils/System.php
@@ -1442,6 +1442,7 @@ public static function flushCache() {
       Civi::cache('groups')->flush();
       Civi::cache('navigation')->flush();
       Civi::cache('customData')->flush();
+      Civi::cache('contactSubTypes')->clear();
       CRM_Extension_System::singleton()->getCache()->flush();
       CRM_Cxn_CiviCxnHttp::singleton()->getCache()->flush();
     }
diff --git a/Civi/Core/Container.php b/Civi/Core/Container.php
index 9c78f0b3126c..704c9cf370f7 100644
--- a/Civi/Core/Container.php
+++ b/Civi/Core/Container.php
@@ -159,6 +159,7 @@ public function createContainer() {
       'navigation' => 'navigation',
       'customData' => 'custom data',
       'fields' => 'contact fields',
+      'contactSubTypes' => 'contactSubTypes',
     ];
     foreach ($basicCaches as $cacheSvc => $cacheGrp) {
       $definitionParams = [
@@ -168,7 +169,7 @@ public function createContainer() {
       // For Caches that we don't really care about the ttl for and/or maybe accessed
       // fairly often we use the fastArrayDecorator which improves reads and writes, these
       // caches should also not have concurrency risk.
-      $fastArrayCaches = ['groups', 'navigation', 'customData', 'fields'];
+      $fastArrayCaches = ['groups', 'navigation', 'customData', 'fields', 'contactSubTypes'];
       if (in_array($cacheSvc, $fastArrayCaches)) {
         $definitionParams['withArray'] = 'fast';
       }