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 dc3a60a24d..972b404b88 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
@@ -6,6 +6,10 @@
         "desc": "Configure a wrong type in AAA table.",
         "eStrKey": "InvalidValue"
     },
+    "AAA_TEST_WRONG_LOGIN": {
+        "desc": "Configure a wrong type in AAA table.",
+        "eStr": ["Invalid login choice"]
+    },
     "AAA_TEST_WRONG_FAILTHROUGH": {
         "desc": "Configure a wrong failthrough in AAA table.",
         "eStrKey": "Pattern",
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 5b05fc3330..fbf63f994c 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
@@ -24,6 +24,16 @@
         }
     },
 
+    "AAA_TEST_WRONG_LOGIN": {
+        "sonic-system-aaa:sonic-system-aaa": {
+            "sonic-system-aaa:AAA": {
+                "AAA_LIST": [{
+                        "login": "locallll"
+                }]
+            }
+        }
+    },
+
     "AAA_TEST_WRONG_FAILTHROUGH": {
         "sonic-system-aaa:sonic-system-aaa": {
             "sonic-system-aaa:AAA": {
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 5df05d475d..c3a4421269 100644
--- a/src/sonic-yang-models/yang-models/sonic-system-aaa.yang
+++ b/src/sonic-yang-models/yang-models/sonic-system-aaa.yang
@@ -30,8 +30,12 @@ module sonic-system-aaa {
                 }
 
                 leaf login {
-                    type string;
-                    description "AAA authentication/authorization/accounting methods - local/tacacs+/disable";
+                    type string {
+                        pattern '((tacacs\+|local|radius|default),)*(tacacs\+|local|radius|default)' {
+                            error-message "Invalid login choice";
+                        }
+                    }
+                    description "AAA authentication/authorization/accounting methods - radius/tacacs+/local/default";
                     default "local";
                 }