diff --git a/fsw/shared/src/cfe_psp_module.c b/fsw/shared/src/cfe_psp_module.c
index 1140c63f..1fa74d83 100644
--- a/fsw/shared/src/cfe_psp_module.c
+++ b/fsw/shared/src/cfe_psp_module.c
@@ -41,35 +41,53 @@
 #define CFE_PSP_MODULE_INDEX_MASK 0xFFFF
 #endif
 
-static uint32 CFE_PSP_ModuleCount = 0;
+/*
+ * Internal/base modules typically should not be the subject
+ * of a call to CFE_PSP_Module_FindByName or GetAPI,
+ * so they are assigned IDs at the END of the space,
+ * this makes them unique but they are otherwise not used
+ *
+ * Reserve the last 256 entries for base modules
+ */
+#define CFE_PSP_INTERNAL_MODULE_BASE ((CFE_PSP_MODULE_BASE | CFE_PSP_MODULE_INDEX_MASK) & ~0xFF)
+
+static uint32 CFE_PSP_ConfigPspModuleListLength = 0;
 
 /***************************************************
  * Function Name: CFE_PSP_ModuleInitList
  *
  * Helper function to initialize a list of modules (not externally called)
+ * Returns the number of modules initialized
  */
-void CFE_PSP_ModuleInitList(CFE_StaticModuleLoadEntry_t *ListPtr)
+uint32_t CFE_PSP_ModuleInitList(uint32 BaseId, CFE_StaticModuleLoadEntry_t *ListPtr)
 {
     CFE_StaticModuleLoadEntry_t *Entry;
     CFE_PSP_ModuleApi_t *        ApiPtr;
+    uint32                       ModuleCount;
+    uint32                       ModuleId;
 
     /*
      * Call the init function for all statically linked modules
      */
-    Entry = ListPtr;
+    Entry       = ListPtr;
+    ModuleCount = 0;
     if (Entry != NULL)
     {
         while (Entry->Name != NULL)
         {
-            ApiPtr = (CFE_PSP_ModuleApi_t *)Entry->Api;
+            ApiPtr   = (CFE_PSP_ModuleApi_t *)Entry->Api;
+            ModuleId = BaseId + ModuleCount;
             if ((uint32)ApiPtr->ModuleType != CFE_PSP_MODULE_TYPE_INVALID && ApiPtr->Init != NULL)
             {
-                (*ApiPtr->Init)(CFE_PSP_MODULE_BASE | CFE_PSP_ModuleCount);
+                printf("CFE_PSP: initializing module \'%s\' with ID %08lx\n", Entry->Name, (unsigned long)ModuleId);
+                (*ApiPtr->Init)(ModuleId);
             }
             ++Entry;
-            ++CFE_PSP_ModuleCount;
+            ++ModuleCount;
         }
     }
+
+    return ModuleCount;
 }
 
 /***************************************************
@@ -80,10 +98,11 @@ void CFE_PSP_ModuleInitList(CFE_StaticModuleLoadEntry_t *ListPtr)
 void CFE_PSP_ModuleInit(void)
 {
     /* First initialize the fixed set of modules for this PSP */
-    CFE_PSP_ModuleInitList(CFE_PSP_BASE_MODULE_LIST);
+    CFE_PSP_ModuleInitList(CFE_PSP_INTERNAL_MODULE_BASE, CFE_PSP_BASE_MODULE_LIST);
 
     /* Then initialize any user-selected extension modules */
-    CFE_PSP_ModuleInitList(GLOBAL_CONFIGDATA.PspModuleList);
+    /* Only these modules can be used with CFE_PSP_Module_GetAPIEntry or CFE_PSP_Module_FindByName */
+    CFE_PSP_ConfigPspModuleListLength = CFE_PSP_ModuleInitList(CFE_PSP_MODULE_BASE, GLOBAL_CONFIGDATA.PspModuleList);
 }
 
 /***************************************************
@@ -100,7 +119,7 @@ int32 CFE_PSP_Module_GetAPIEntry(uint32 PspModuleId, CFE_PSP_ModuleApi_t **API)
     if ((PspModuleId & ~CFE_PSP_MODULE_INDEX_MASK) == CFE_PSP_MODULE_BASE)
     {
         LocalId = PspModuleId & CFE_PSP_MODULE_INDEX_MASK;
-        if (LocalId < CFE_PSP_ModuleCount)
+        if (LocalId < CFE_PSP_ConfigPspModuleListLength)
         {
             *API   = (CFE_PSP_ModuleApi_t *)GLOBAL_CONFIGDATA.PspModuleList[LocalId].Api;
             Result = CFE_PSP_SUCCESS;
@@ -124,7 +143,7 @@ int32 CFE_PSP_Module_FindByName(const char *ModuleName, uint32 *PspModuleId)
     Entry  = GLOBAL_CONFIGDATA.PspModuleList;
     Result = CFE_PSP_INVALID_MODULE_NAME;
     i      = 0;
-    while (i < CFE_PSP_ModuleCount)
+    while (i < CFE_PSP_ConfigPspModuleListLength)
     {
         if (strcmp(Entry->Name, ModuleName) == 0)
         {