diff --git a/autogen/agentchat/contrib/gpt_assistant_agent.py b/autogen/agentchat/contrib/gpt_assistant_agent.py
index e5916781cd67..a6ab3372f879 100644
--- a/autogen/agentchat/contrib/gpt_assistant_agent.py
+++ b/autogen/agentchat/contrib/gpt_assistant_agent.py
@@ -3,6 +3,7 @@
 import json
 import time
 import logging
+import copy
 
 from autogen import OpenAIWrapper
 from autogen.oai.openai_utils import retrieve_assistants_by_name
@@ -52,12 +53,26 @@ def __init__(
                 - verbose (bool): If set to True, enables more detailed output from the assistant thread.
                 - Other kwargs: Except verbose, others are passed directly to ConversableAgent.
         """
+
+        self._verbose = kwargs.pop("verbose", False)
+        super().__init__(
+            name=name, system_message=instructions, human_input_mode="NEVER", llm_config=llm_config, **kwargs
+        )
+
+        if llm_config is False:
+            raise ValueError("llm_config=False is not supported for GPTAssistantAgent.")
+
         # Use AutoGen OpenAIWrapper to create a client
-        openai_client_cfg = None
-        model_name = "gpt-4-1106-preview"
-        if llm_config and llm_config.get("config_list") is not None and len(llm_config["config_list"]) > 0:
-            openai_client_cfg = llm_config["config_list"][0].copy()
-            model_name = openai_client_cfg.pop("model", "gpt-4-1106-preview")
+        model_name = "gpt-4-0125-preview"
+        openai_client_cfg = copy.deepcopy(llm_config)
+        # GPTAssistantAgent's azure_deployment param may cause NotFoundError (404) in client.beta.assistants.list()
+        # See: https://github.com/microsoft/autogen/pull/1721
+        if openai_client_cfg.get("config_list") is not None and len(openai_client_cfg["config_list"]) > 0:
+            model_name = openai_client_cfg["config_list"][0].pop("model", "gpt-4-0125-preview")
+        else:
+            model_name = openai_client_cfg.pop("model", "gpt-4-0125-preview")
+
+        logger.warning("OpenAI client config of GPTAssistantAgent(%s) - model: %s", name, model_name)
 
         oai_wrapper = OpenAIWrapper(**openai_client_cfg)
         if len(oai_wrapper._clients) > 1:
@@ -143,11 +158,6 @@ def __init__(
                 # Tools are specified but overwrite_tools is False; do not update the assistant's tools
                 logger.warning("overwrite_tools is False. Using existing tools from assistant API.")
 
-        self._verbose = kwargs.pop("verbose", False)
-        super().__init__(
-            name=name, system_message=instructions, human_input_mode="NEVER", llm_config=llm_config, **kwargs
-        )
-
         # lazily create threads
         self._openai_threads = {}
         self._unread_index = defaultdict(int)
diff --git a/test/agentchat/contrib/test_gpt_assistant.py b/test/agentchat/contrib/test_gpt_assistant.py
index 5419c99492a8..23e865c4a9f7 100644
--- a/test/agentchat/contrib/test_gpt_assistant.py
+++ b/test/agentchat/contrib/test_gpt_assistant.py
@@ -17,7 +17,21 @@
 
 if not skip:
     openai_config_list = autogen.config_list_from_json(
-        OAI_CONFIG_LIST, file_location=KEY_LOC, filter_dict={"api_type": ["openai"]}
+        OAI_CONFIG_LIST,
+        file_location=KEY_LOC,
+        # The Retrieval tool requires at least gpt-3.5-turbo-1106 (newer versions are supported) or gpt-4-turbo-preview models.
+        # https://platform.openai.com/docs/models/overview
+        filter_dict={
+            "api_type": ["openai"],
+            "model": [
+                "gpt-4-turbo-preview",
+                "gpt-4-0125-preview",
+                "gpt-4-1106-preview",
+                "gpt-3.5-turbo",
+                "gpt-3.5-turbo-0125",
+                "gpt-3.5-turbo-1106",
+            ],
+        },
     )
     aoai_config_list = autogen.config_list_from_json(
         OAI_CONFIG_LIST,
@@ -41,7 +55,8 @@ def test_config_list() -> None:
 )
 def test_gpt_assistant_chat() -> None:
     for gpt_config in [openai_config_list, aoai_config_list]:
-        _test_gpt_assistant_chat(gpt_config)
+        _test_gpt_assistant_chat({"config_list": gpt_config})
+        _test_gpt_assistant_chat(gpt_config[0])
 
 
 def _test_gpt_assistant_chat(gpt_config) -> None:
@@ -68,7 +83,7 @@ def ask_ossinsight(question: str) -> str:
     name = f"For test_gpt_assistant_chat {uuid.uuid4()}"
     analyst = GPTAssistantAgent(
         name=name,
-        llm_config={"tools": [{"type": "function", "function": ossinsight_api_schema}], "config_list": gpt_config},
+        llm_config={"tools": [{"type": "function", "function": ossinsight_api_schema}], **gpt_config},
         instructions="Hello, Open Source Project Analyst. You'll conduct comprehensive evaluations of open source projects or organizations on the GitHub platform",
     )
     try: