diff --git a/src/sonic-yang-models/tests/yang_model_tests/tests/aaa.json b/src/sonic-yang-models/tests/yang_model_tests/tests/aaa.json
index 5ecede4267f..dc3a60a24df 100644
--- a/src/sonic-yang-models/tests/yang_model_tests/tests/aaa.json
+++ b/src/sonic-yang-models/tests/yang_model_tests/tests/aaa.json
@@ -8,7 +8,8 @@
     },
     "AAA_TEST_WRONG_FAILTHROUGH": {
         "desc": "Configure a wrong failthrough in AAA table.",
-        "eStrKey": "InvalidValue"
+        "eStrKey": "Pattern",
+        "eStr": ["false|true|False|True"]
     },
     "AAA_AUTHORIZATION_TEST": {
         "desc": "Configure an authorization type in AAA table."
diff --git a/src/sonic-yang-models/tests/yang_model_tests/tests_config/aaa.json b/src/sonic-yang-models/tests/yang_model_tests/tests_config/aaa.json
index 87b03ecd9d1..5b05fc33303 100644
--- a/src/sonic-yang-models/tests/yang_model_tests/tests_config/aaa.json
+++ b/src/sonic-yang-models/tests/yang_model_tests/tests_config/aaa.json
@@ -5,8 +5,10 @@
                 "AAA_LIST": [{
                         "type": "authentication",
                         "login": "tacacs+,local",
-                        "failthrough": "true",
-                        "debug": "true"
+                        "failthrough": "True",
+                        "fallback": "True",
+                        "trace": "True",
+                        "debug": "True"
                 }]
             }
         }
diff --git a/src/sonic-yang-models/yang-models/sonic-system-aaa.yang b/src/sonic-yang-models/yang-models/sonic-system-aaa.yang
index 01e342b2691..5df05d475de 100644
--- a/src/sonic-yang-models/yang-models/sonic-system-aaa.yang
+++ b/src/sonic-yang-models/yang-models/sonic-system-aaa.yang
@@ -3,6 +3,10 @@ module sonic-system-aaa {
     prefix ssys;
     yang-version 1.1;
 
+    import sonic-types {
+        prefix stypes;
+    }
+
     revision 2021-10-12 {
         description "Add AAA authorization/accounting support.";
     }
@@ -32,17 +36,28 @@ module sonic-system-aaa {
                 }
 
                 leaf failthrough {
-                    type boolean;
+                    type stypes:boolean_type;
                     description "When set to true, authentication is attempted on next configured server/local in the list upon failure.";
-                    default false;
+                    default False;
+                }
+
+                leaf fallback {
+                    type stypes:boolean_type;
+                    description "Allow AAA fallback";
+                    default False;
                 }
                 
                 leaf debug {
-                    type boolean;
+                    type stypes:boolean_type;
                     description "Enable/disable AAA debugging";
-                    default false;
+                    default False;
                 }
 
+                leaf trace {
+                    type stypes:boolean_type;
+                    description "AAA packet trace";
+                    default False;
+                }
             }
         }
     }